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The contrast sensitivity function (CSF) is routinely assessed in clinical evaluation of vision and is the primary limiting factor in how well one sees. CSF improvements are typically brought about by correction of the optics of the eye with eyeglasses, contact lenses or surgery. We found that the very act of action video game playing also enhanced contrast sensitivity, providing a complementary route to eyesight improvement.

As a spoken word unfolds over time, it is temporarily consistent with the acoustic forms of multiple words. Previous behavioral research has shown that, in the face of temporary ambiguity about how a word will end, multiple candidate words are briefly activated. Here, we provide neural imaging evidence that lexical candidates only temporarily consistent with the input activate perceptually based semantic representations. An artificial lexicon and novel visual environment were used to target human MT/V5 and an area anterior to it which have been shown to be recruited during the reading of motion words. Participants learned words that referred to novel objects and to motion or color/texture changes that the objects underwent. The lexical items corresponding to the change events were organized into phonologically similar pairs differing only in the final syllable. Upon hearing spoken scene descriptions in a posttraining verification task, participants showed greater activation in the left hemisphere anterior extent of MT/V5 when motion words were heard than when nonmotion words were heard. Importantly, when a nonmotion word was heard, the level of activation in the anterior extent of MT/V5 was modulated by whether there was a phonologically related competitor that was a motion word rather than another nonmotion word. These results provide evidence of activation of a perceptual brain region in response to the semantics of a word while lexical competition is in process and before the word is fully recognized.

Adult brain plasticity, although possible, is often difficult to elicit. Training regimens in adults can produce specific improvements on the trained task without leading to general enhancements that would improve quality of life. This paper considers the case of playing action video games as a way to induce widespread enhancement in vision.We review the range of visual skills altered by action video game playing as well as the game components important in promoting visual plasticity. Further, we discuss what these results might mean in terms of rehabilitation for different patient populations.

Capacity limits in linguistic short-term memory (STM) are typically measured with forward span tasks in which participants are asked to recall lists of words in the order presented. Using such tasks, native signers of American Sign Language (ASL) exhibit smaller spans than native speakers ([Boutla, M., Supalla, T., Newport, E. L., & Bavelier, D. (2004). Short-term memory span: Insights from sign language. Nature Neuroscience, 7(9), 997-1002]). Here, we test the hypothesis that this population difference reflects differences in the way speakers and signers maintain temporal order information in short-term memory. We show that native signers differ from speakers on measures of short-term memory that require maintenance of temporal order of the tested materials, but not on those in which temporal order is not required. In addition, we show that, in a recall task with free order, bilingual subjects are more likely to recall in temporal order when using English than ASL. We conclude that speakers and signers do share common short-term memory processes. However, whereas short-term memory for spoken English is predominantly organized in terms of temporal order, we argue that this dimension does not play as great a role in signers' short-term memory. Other factors that may affect STM processes in signers are discussed.

Most research on reading skill acquisition in deaf individuals has been conducted from the perspective of a hearing child learning to read. This approach may limit our understanding of how a deaf child approaches the task of learning to read and successfully acquires reading skills. An alternative approach is to consider how the cognitive skills that a deaf child brings to the reading task may influence the route by which he or she achieves reading fluency. A review of the literature on visual spatial attention suggests that deaf individuals are more distracted by visual information in the parafovea and periphery. We discuss how this may have an influence upon the perceptual processing of written text in deaf students.

Playing action video games enhances several different aspects of visual processing; however, the mechanisms underlying this improvement remain unclear. Here we show that playing action video games can alter fundamental characteristics of the visual system, such as the spatial resolution of visual processing across the visual field. To determine the spatial resolution of visual processing, we measured the smallest distance a distractor could be from a target without compromising target identification. This approach exploits the fact that visual processing is hindered as distractors are brought close to the target, a phenomenon known as crowding. Compared with nonplayers, action-video-game players could tolerate smaller target-distractor distances. Thus, the spatial resolution of visual processing is enhanced in this population. Critically, similar effects were observed in non-video-game players who were trained on an action video game; this result verifies a causative relationship between video-game play and augmented spatial resolution.

The loss of one sensory modality can lead to a reorganization of the other intact sensory modalities. In the case of individuals who are born profoundly deaf, there is growing evidence of changes in visual functions. Specifically, deaf individuals demonstrate enhanced visual processing in the periphery, and in particular enhanced peripheral visual attention. To further characterize those aspects of visual attention that may be modified by deafness, deaf and hearing individuals were compared on the Attentional Network Test (ANT). The ANT was selected as it provides a measure of the efficiency of three neurally distinct subsystems of visual attention: alerting, orienting and executive control. The alerting measure refers to the efficiency with which a temporal cue is used to direct attention towards a target event, and the orienting measure is an indicator of the efficiency with which a spatial cue focuses attention upon that target's spatial location. The executive control measure, on the other hand, is an indicator of the amount of interference from peripheral flankers on processing that central target. In two separate experiments, deaf and hearing individuals displayed similar alerting and orienting abilities indicating comparable attention across populations. As predicted by enhanced peripheral attention, deaf subjects were found to have larger flanker interference effects than hearing subjects. These results indicate that not all aspects of visual attention are modified by early deafness, suggesting rather specific effects of cross-modal plasticity.

The authors investigated the effect of action gaming on the spatial distribution of attention. The authors used the flanker compatibility effect to separately assess center and peripheral attentional resources in gamers versus nongamers. Gamers exhibited an enhancement in attentional resources compared with nongamers, not only in the periphery but also in central vision. The authors then used a target localization task to unambiguously establish that gaming enhances the spatial distribution of visual attention over a wide field of view. Gamers were more accurate than nongamers at all eccentricities tested, and the advantage held even when a concurrent center task was added, ruling out a trade-off between central and peripheral attention. By establishing the causal role of gaming through training studies, the authors demonstrate that action gaming enhances visuospatial attention throughout the visual field.

Short-term memory (STM) is thought to be limited in capacity to about 7 ± 2 items for linguistic materials and 4 ± 1 items for visuospatial information (Baddeley & Logie, 1999; Cowan, 2001). Recently, we (Boutla, Supalla, Newport, & Bavelier, 2004) challenged this dichotomy between linguistic and visuospatial STM by showing that STM capacity in users of American Sign Language (ASL) is also limited to about 4 or 5 items. This finding suggests that although longer spans appear for speech, spans are not necessarily longer for linguistic materials across all modalities. Wilson and Emmorey (2006) responded that because we evaluated span using digits for English speakers and letters for ASL signers, the difference we reported might have stemmed from stimulus selection rather than language modality. Here we address this claim by reporting an experiment in which we reexamined STM span in English speakers using letters and compared the outcome with results we and Wilson and Emmorey have obtained for ASL signers. It is important to note that the discrepancy between our previous results and those of Wilson and Emmorey is not in the obtained span in signers found by all parties to be around 4 to 5 items (Fig. la). Rather, Wilson and Emmorey disputed whether the digit span of 7 ± 2 in speakers is an appropriate benchmark for comparison with signers. Using letters to measure span in speakers, they found a span of only 5.3, comparable to that of signers. They suggested that there is no difference in span between the two languages. Here we show that their result is not due to their use of letters instead of digits. Rather, in selecting letters that are translations of one another in English and ASL, Wilson and Emmorey failed to control the stimuli in each language for phonological factors known to affect span size. One such crucial factor is phonological similarity. The finding that span is longer for digits than for letters in English speakers is not new (Cavanaugh, 1972). However, this difference has been attributed to the greater phonological similarity of letter names than digit names in English (Conrad & Hull, 1964; Mueller, Seymour, Kieras, & Meyer, 2003). In our previous study, we used letters with signers and digits with speakers to match stimuli in this important regard. Finger-spelled letters are less phonologically similar than number signs in ASL and therefore are more comparable to digits in English speakers. To demonstrate that there is nothing special about letters versus digits, other than the fact that many letter names are highly similar in English (e.g., bee, dee, ee, gee) and thus prone to produce shorter spans, we show here that when phonologically controlled letter materials are used with English speakers, the span of speakers returns to the typical 7 ± 2 range and continues to contrast with the span of signers.

Here, we demonstrate that action video game play enhances subjects' ability in two tasks thought to indicate the number of items that can be apprehended. Using an enumeration task, in which participants have to determine the number of quickly flashed squares, accuracy measures showed a near ceiling performance for low numerosities and a sharp drop in performance once a critical number of squares was reached. Importantly, this critical number was higher by about two items in video game players (VGPs) than in non-video game players (NVGPs). A following control study indicated that this improvement was not due to an enhanced ability to instantly apprehend the numerosity of the display, a process known as subitizing, but rather due to an enhancement in the slower more serial process of counting. To confirm that video game play facilitates the processing of multiple objects at once, we compared VGPs and NVGPs on the multiple object tracking task (MOT), which requires the allocation of attention to several items over time. VGPs were able to successfully track approximately two more items than NVGPs. Furthermore, NVGPs trained on an action video game established the causal effect of game playing in the enhanced performance on the two tasks. Together, these studies confirm the view that playing action video games enhances the number of objects that can be apprehended and suggest that this enhancement is mediated by changes in visual short-term memory skills.

Neuroscientists should help to develop compelling video games that boost brain function and improve well-being, say Daphne Bavelier and Richard J. Davidson.

Short-term memory (STM), or the ability to hold information in mind for a few seconds, is thought to be limited in its capacity to about 7 +/- 2 items. Notably, the average STM capacity when using American Sign Language (ASL) rather than English is only 5 +/- 1 items. Here we show that, contrary to previous interpretations, this difference cannot be attributed to phonological factors, item duration or reduced memory abilities in deaf people. We also show that, despite this difference in STM span, hearing speakers and deaf ASL users have comparable working memory resources during language use, indicating similar abilities to maintain and manipulate linguistic information. The shorter STM span in ASL users therefore confirms the view that the spoken span of 7 +/- 2 is an exception, probably owing to the reliance of speakers on auditory-based rather than visually based representations in linguistic STM, and calls for adjustments in the norms used with deaf individuals.

In a series of three experiments, we tested whether deaf native signers process motion velocity information differently from hearing nonsigners. In Experiment 1, participants watched radially moving dots and were asked to detect the quadrant in which the velocity of the dots had changed. Similar 79% thresholds were observed in the two populations. In Experiments 2 and 3, peripheral and central thresholds were assessed separately as previous studies suggest early deafness leads mainly to changes in the processing of visual peripheral information. Neither condition produced an overall population difference. These negative results were not due to a lack of sensitivity in our experiments. Indeed, as has been previously reported, deaf native signers exhibited better thresholds in the right than in the left visual field, whereas the opposite pattern was observed in the hearing. This effect appears triggered by experience with American Sign Language (ASL) rather than deafness per se. Overall, this study confirms that early deafness does not enhance motion processing, and suggests that most of the changes previously described in the literature are instead attributable to changes in attention, and possibly special alterations of attention-to-motion processes.

The prior entry hypothesis contends that attention accelerates sensory processing, shortening the time to perception. Typical observations supporting the hypothesis may be explained equally well by response biases, changes in decision criteria, or sensory facilitation. In a series of experiments conducted to discriminate among the potential mechanisms, observers judged the simultaneity or temporal order of two stimuli, to one of which attention was oriented by exogenous, endogenous, gaze-directed, or multiple exogenous cues. The results suggest that prior entry effects are primarily caused by sensory facilitation and attentional modifications of the decision mechanism, with only a small part possibly due to an attention-dependent sensory acceleration.

The results from the language studies taken as a whole point to different developmental time courses and developmental vulnerabilities of aspects of grammatical and semantic/lexical processing. They thus provide support for conceptions of language that distinguish these subprocesses within language. Similarly, following auditory deprivation, processes associated with the dorsal visual pathway were more altered than were functions associated with the ventral pathway, providing support for conceptions of visual system organization that distinguish functions along these lines. Could the effects observed in blind and deaf adults be accounted for, at least in part, by the redundant connectivity of the immature human brain? One way we tested this hypothesis was to study the differentiation of visual and auditory sensory responses in normal development (Neville, 1995). In normal adults, auditory stimuli elicit ERP responses that are large over temporal brain regions but small or absent over occipital regions. By contrast, in 6-month-old children we observed that auditory ERPs are equally large over temporal and visual brain regions, consistent with the idea that there is less specificity and more redundancy of connections between the auditory and visual cortex at this time. Between 6 and 36 months, however, we observed a gradual decrease in the amplitude of the auditory ERP over visual areas, while the amplitude over the temporal areas was unchanged. These results suggest that early in human development, there exists a redundancy of connections between auditory and visual areas and that this overlap gradually decreases after birth. This loss of redundancy may be a boundary condition that determines when sensory deprivation can result in alterations in the organization of remaining sensory systems. The considerable variability in timing of sensitive periods may also be in part due to temporal differences in the occurrence of redundancy within different systems. Ongoing studies of infants and children employing different types of stimuli will test for the specificity of these effects (Mitchell et al., 1999). Differences in the degree of plasticity may also be due to differences in the overall level of redundant connectivity within different systems. For example, it may be that aspects of sensory systems that are specialized for high spatial acuity (e.g., central vision and central audition) exhibit fewer developmental redundancies, decreased modifiability and more specificity than those displaying less acuity and precision (e.g., peripheral representations within vision and audition). There is some evidence for this hypothesis within the visual system (Chalupa and Dreher, 1991). In addition, there may be molecular differences between systems displaying different levels and patterns of experience-dependent plasticity. It is of interest that all levels of the dorsal pathway of the visual system, which in the studies reviewed here shows a high level of modifiability, displays strong immunoreactivity for the monoclonal antibody CAT 301 in macaque monkeys (DeYoe et al., 1990). By contrast there is very little labeling within the ventral visual pathway. Moreover, the expression of CAT 301 immunoreactivity shows marked experience-dependent plasticity, suggesting it may play a role in the guidance and/or stabilization of synaptic structure (Sur et al., 1988). Further research along these lines within the auditory system and in animal models of sensory deprivation and other developmental disorders may elucidate the role of specific molecular factors in the developmental plasticity of different neural systems. A related, more general hypothesis that may account for the different patterns of plasticity within both vision and language is that systems employing fundamentally different learning mechanisms (perhaps mediated by different anatomical and molecular substrates) display different patterns of developmental plasticity. It may be that systems that display experience-dependent change throughout life, including the topography of sensory maps (Merzenich et al., 1988; Gilbert, 1995; Kaas, 1995), lexical acquisition (i.e. object-word associations), and the establishment of form, face, and object representations (i.e., ventral pathway functions) rely upon very general, associative learning mechanisms that permit learning and adaptation throughout life. By contrast, systems that are important for computing dynamically shifting relations among locations, objects and events (including the dorsal visual pathway and the systems of the brain that mediate grammar) appear dependent on and modifiable by experience primarily during more limited periods in development. This could account for both the greater developmental deficits and enhancements of dorsal pathway function following various developmental anomalies and for the greater effects of altered language experience on grammatical functions. Further research is necessary to characterize systems that become constrained in this way and those that can be modified throughout life. This type of developmental evidence can contribute to fundamental descriptions of the architecture of different cognitive systems and can guide future studies of the cellular and molecular mechanisms important in neuroplasticity. Additionally, in the long run, they may contribute to the design of educational and habilitative programs for both normally and abnormally developing children.

There is much anecdotal suggestion of improved visual skills in congenitally deaf individuals. However, this claim has only been met by mixed results from careful investigations of visual skills in deaf individuals. Psychophysical assessments of visual functions have failed, for the most part, to validate the view of enhanced visual skills after deafness. Only a few studies have shown an advantage for deaf individuals in visual tasks. Interestingly, all of these studies share the requirement that participants process visual information in their peripheral visual field under demanding conditions of attention. This work has led us to propose that congenital auditory deprivation alters the gradient of visual attention from central to peripheral field by enhancing peripheral processing. This hypothesis was tested by adapting a search task from Lavie and colleagues in which the interference from distracting information on the search task provides a measure of attentional resources. These authors have established that during an easy central search for a target, any surplus attention remaining will involuntarily process a peripheral distractor that the subject has been instructed to ignore. Attentional resources can be measured by adjusting the difficulty of the search task to the point at which no surplus resources are available for the distractor. Through modification of this paradigm, central and peripheral attentional resources were compared in deaf and hearing individuals. Deaf individuals possessed greater attentional resources in the periphery but less in the center when compared to hearing individuals. Furthermore, based on results from native hearing signers, it was shown that sign language alone could not be responsible for these changes. We conclude that auditory deprivation from birth leads to compensatory changes within the visual system that enhance attentional processing of the peripheral visual field.

The results from the language studies taken as a whole point to different developmental time courses and developmental vulnerabilities of aspects of grammatical and semantic/lexical processing. They thus provide support for conceptions of language that distinguish these subprocesses within language. Similarly, following auditory deprivation, processes associated with the dorsal visual pathway were more altered than were functions associated with the ventral pathway, providing support for conceptions of visual system organization that distinguish functions along these lines. Could the effects observed in blind and deaf adults be accounted for, at least in part, by the redundant connectivity of the immature human brain? One way we tested this hypothesis was to study the differentiation of visual and auditory sensory responses in normal development (Neville, 1995). In normal adults, auditory stimuli elicit ERP responses that are large over temporal brain regions but small or absent over occipital regions. By contrast, in 6-month-old children we observed that auditory ERPs are equally large over temporal and visual brain regions, consistent with the idea that there is less specificity and more redundancy of connections between the auditory and visual cortex at this time. Between 6 and 36 months, however, we observed a gradual decrease in the amplitude of the auditory ERP over visual areas, while the amplitude over the temporal areas was unchanged. These results suggest that early in human development, there exists a redundancy of connections between auditory and visual areas and that this overlap gradually decreases after birth. This loss of redundancy may be a boundary condition that determines when sensory deprivation can result in alterations in the organization of remaining sensory systems. The considerable variability in timing of sensitive periods may also be in part due to temporal differences in the occurrence of redundancy within different systems. Ongoing studies of infants and children employing different types of stimuli will test for the specificity of these effects (Mitchell et al., 1999). Differences in the degree of plasticity may also be due to differences in the overall level of redundant connectivity within different systems. For example, it may be that aspects of sensory systems that are specialized for high spatial acuity (e.g., central vision and central audition) exhibit fewer developmental redundancies, decreased modifiability and more specificity than those displaying less acuity and precision (e.g., peripheral representations within vision and audition). There is some evidence for this hypothesis within the visual system (Chalupa and Dreher, 1991). In addition, there may be molecular differences between systems displaying different levels and patterns of experience-dependent plasticity. It is of interest that all levels of the dorsal pathway of the visual system, which in the studies reviewed here shows a high level of modifiability, displays strong immunoreactivity for the monoclonal antibody CAT 301 in macaque monkeys (DeYoe et al., 1990). By contrast there is very little labeling within the ventral visual pathway. Moreover, the expression of CAT 301 immunoreactivity shows marked experience-dependent plasticity, suggesting it may play a role in the guidance and/or stabilization of synaptic structure (Sur et al., 1988). Further research along these lines within the auditory system and in animal models of sensory deprivation and other developmental disorders may elucidate the role of specific molecular factors in the developmental plasticity of different neural systems. A related, more general hypothesis that may account for the different patterns of plasticity within both vision and language is that systems employing fundamentally different learning mechanisms (perhaps mediated by different anatomical and molecular substrates) display different patterns of developmental plasticity. It may be that systems that display experience-dependent change throughout life, including the topography of sensory maps (Merzenich et al., 1988; Gilbert, 1995; Kaas, 1995), lexical acquisition (i.e. object-word associations), and the establishment of form, face, and object representations (i.e., ventral pathway functions) rely upon very general, associative learning mechanisms that permit learning and adaptation throughout life. By contrast, systems that are important for computing dynamically shifting relations among locations, objects and events (including the dorsal visual pathway and the systems of the brain that mediate grammar) appear dependent on and modifiable by experience primarily during more limited periods in development. This could account for both the greater developmental deficits and enhancements of dorsal pathway function following various developmental anomalies and for the greater effects of altered language experience on grammatical functions. Further research is necessary to characterize systems that become constrained in this way and those that can be modified throughout life. This type of developmental evidence can contribute to fundamental descriptions of the architecture of different cognitive systems and can guide future studies of the cellular and molecular mechanisms important in neuroplasticity. Additionally, in the long run, they may contribute to the design of educational and habilitative programs for both normally and abnormally developing children.

Animal studies have shown that sensory deprivation in one modality can have striking effects on the development of the remaining modalities. Although recent studies of deaf and blind humans have also provided convincing behavioural, electrophysiological and neuroimaging evidence of increased capabilities and altered organization of spared modalities, there is still much debate about the identity of the brain systems that are changed and the mechanisms that mediate these changes. Plastic changes across brain systems and related behaviours vary as a function of the timing and the nature of changes in experience. This specificity must be understood in the context of differences in the maturation rates and timing of the associated critical periods, differences in patterns of transiently existing connections, and differences in molecular factors across brain systems.

Humans can reach for objects with their hands whether the objects are seen, heard or touched. Thus, the position of objects is recoded in a joint-centered frame of reference regardless of the sensory modality involved. Our study indicates that this frame of reference is not the only one shared across sensory modalities. The location of reaching targets is also encoded in eye-centered coordinates, whether the targets are visual, auditory, proprioceptive or imaginary. Furthermore, the remembered eye-centered location is updated after each eye and head movement. This is quite surprising since, in principle, a reaching motor command can be computed from any non-visual modality without ever recovering the eye-centered location of the stimulus. This finding may reflect the predominant role of vision in human spatial perception.

Two books reach opposite verdicts on how the Internet affects us, find Daphne Bavelier and C. Shawn Green. - The Shallows: What the Internet is Doing to Our Brains/How the Internet is Changing the Way We Think, Read and Remember. Nicholas Carr W. W. Norton/Atlantic Books: 2010. - I Live in the Future & Here's How it Works: Why Your World, Work, and Brain are Being Creatively Disrupted Nick Bilton Crown: 2010. 304 pp

This functional magnetic resonance imaging study investigated the impact of early auditory deprivation and/or use of a visuospatial language [American sign language (ASL)] on the organization of neural systems important in visual motion processing by comparing hearing controls with deaf and hearing native signers. Participants monitored moving flowfields under different conditions of spatial and featural attention. Recruitment of the motion-selective area MT–MST in hearing controls was observed to be greater when attention was directed centrally and when the task was to detect motion features, confirming previous reports that the motion network is selectively modulated by different aspects of attention. More importantly, we observed marked differences in the recruitment of motion-related areas as a function of early experience. First, the lateralization of MT–MST was found to shift toward the left hemisphere in early signers, suggesting that early exposure to ASL leads to a greater reliance on the left MT–MST. Second, whereas the two hearing populations displayed more MT–MST activation under central than peripheral attention, the opposite pattern was observed in deaf signers, indicating enhanced recruitment of MT–MST during peripheral attention after early deafness. Third, deaf signers, but neither of the hearing populations, displayed increased activation of the posterior parietal cortex, supporting the view that parietal functions are modified after early auditory deprivation. Finally, only in deaf signers did attention to motion result in enhanced recruitment of the posterior superior temporal sulcus, establishing for the first time in humans that this polymodal area is modified after early sensory deprivation. Together these results highlight the functional and regional specificity of neuroplasticity in humans.

Powerful advances in neuroimaging techniques have added to and refined classical descriptions of the neurobiology of language in adults. Recent studies have employed these methodologies to study the nature and extent of plasticity of language-relevant aspects of cerebral organization in adults, in early and late bilinguals and in people who have acquired language through different modalities. Studies of children have documented dynamic shifts in cerebral organization over the course of language acquisition. Each of these different approaches has revealed constraints on the identity of the neural systems that mediate language; these studies have also described the marked and specific effects of language experience on the organization of these systems.

Mazoyer et al.[22xThe cortical representation of speech. Mazoyer, B.M et al. J. Cogn. Neurosci. 1993; 5: 467–479Crossref | PubMedSee all References[22]contrasted passive listening of French (the subject native language) to passive listening to an unfamiliar language, Tamil. While overall left perisylvian sites showed greater activation, RH activation was observed in left and right superior temporal lobe and left and right temporal poles. Price et al. (Ref. [23xHearing and saying: the functional neuroanatomy of auditory word processing. Price, C.J et al. Brain. 1996; 119: 919–931Crossref | PubMed | Scopus (333)See all References[23], experiment 3) reported limited RH activation in a condition contrasting listening to lists of single words with listening to backwards words. In several reading tasks, RH activity has also been observed. Activity in the middle portion of the superior temporal sulcus of the RH has been reported by Bavelier et al.[24xSentence reading: an fMRI study at 4T. Bavelier, D et al. J. Cogn. Neurosci. 1997; 9: 664–686Crossref | PubMedSee all References[24]when English native speakers read well-formed sentences contrasted with the presentation of consonant strings. Bavelier et al. suggest aspects of semantic encoding may engage right temporal lobe areas. Stromswold et al.[25xLocalization of syntactic comprehension by positron emission tomography. Stromswold, K et al. Brain Lang. 1996; 52: 452–473Crossref | PubMed | Scopus (418)See all References[25]compared rCBF during the reading of syntactically complex sentences. Significant activation was observed in right middle temporal gyrus when subjects read syntactically complex sentences compared to less complex constructions. In a related finding, Just et al.[26xBrain activation modulated by sentence comprehension. Just, M.A et al. Science. 1996; 274: 114–116Crossref | PubMed | Scopus (718)See all References[26]reported both left and RH activity in a task requiring reading of sentences with increasing syntactic complexity. They reported activity in both left and RH sites (corresponding to Broca's and Wernicke's areas) that was modulated by sentence complexity, though the RH activity was approximately 25% of the amount of activity observed in the left-hemisphere sites. These authors speculate that while the left hemisphere is usually the primary site of language comprehension, the right hemisphere may be recruited in times of high demand.

Carriers of blue cone monochromacy have fewer cone photoreceptors than normal. Here we examine how this disruption at the level of the retina affects visual function and cortical organization in these individuals. Visual resolution and contrast sensitivity was measured at the preferred retinal locus of fixation and visual resolution was tested at two eccentric locations (2.5° and 8°) with spectacle correction only. Adaptive optics corrected resolution acuity and cone spacing were simultaneously measured at several locations within the central fovea with adaptive optics scanning laser ophthalmoscopy (AOSLO). Fixation stability was assessed by extracting eye motion data from AOSLO videos. Retinotopic mapping using fMRI was carried out to estimate the area of early cortical regions, including that of the foveal confluence. Without adaptive optics correction, BCM carriers appeared to have normal visual function, with normal contrast sensitivity and visual resolution, but with AO-correction, visual resolution was significantly worse than normal. This resolution deficit is not explained by cone loss alone and is suggestive of an associated loss of retinal ganglion cells. However, despite evidence suggesting a reduction in the number of retinal ganglion cells, retinotopic mapping showed no reduction in the cortical area of the foveal confluence. These results suggest that ganglion cell density may not govern the foveal overrepresentation in the cortex. We propose that it is not the number of afferents, but rather the content of the information relayed to the cortex from the retina across the visual field that governs cortical magnification, as under normal viewing conditions this information is similar in both BCM carriers and normal controls.

Repetition Blindness (RB) is the failure to recall the 2nd instance of a rapidly presented word. Five experiments investigated the orthographic and phonological representations involved in RB. Exps 1 and 2 found that the RB effect between orthographic neighbors is modulated by the relative frequency of the words, but not their absolute frequency. Exp 3 showed that the reduced RB effect between neighbors as compared with identical words is due to the reduced orthographic overlap, not to a lack of morphological or semantic overlap. Exps 4 and 5 showed that the RB effect occurs between phonologically related items, and that phonological and frequency properties of the target's orthographic neighbors affect the size of the effect. It is concluded that orthographic RB and phonological RB are sensitive to the target's neighborhood organization and arise from similar mechanisms, but at different stages of processing.

Action video game play enhances basic visual skills such as crowding acuity and contrast sensitivity (C. S. Green & D. Bavelier, 2007; R. Li, U. Polat, W. Makous, & D. Bavelier, 2009). Here, we ask whether the dynamics of perception may also be altered as a result of playing action games. A backward masking paradigm was used to test the hypothesis that action video game play also alters the temporal dynamics of vision. As predicted, action gamers showed reduced backward masking and an accompanying training study established the causal role of action game play in this enhancement. Implications of this result are discussed in the context of the faster reaction times and enhanced sensitivity also documented after action game play.

Titchener (1908) developed his Law of Prior Entry, that attended stimuli enter consciousness more rapidly that unattended stimuli, based on multimodal experiments which seemed to show that stimuli presented to an attended modality were perceived prior to simultaneous stimuli presented to an unattended modality. More recently, Hikosaka, Miyauchi et al. (1993) and Stelmach & Herdman (1991) have shown that, within the visual modality, exogenous visual cues bias temporal order judgments in favor of the cued target, such that the cued target must be delayed relative to the uncued target in order for participants to be maximally uncertain about the order of the two targets. Jaskowski (1993) showed that the existence of the effect for endogenous cueing depends on the response options, and in any case, both Stelmach & Herdman (1991) and Shore, Spence et al. (2001) agree that the effect of endogenous cueing is smaller than for exogenous cueing. Frey (1990) and Shore, Spence et al. (2001) have shown that instructions can affect the size of the attentional effect on order judgments. From this literature it is clear that temporal order judgments can be affected by nonattentional factors. The reduction or elimination of the effect with the endogenous cues suggests that the exogenous cues may have effects on order judgments beyond simple attentional effects.