Evidence for perceptual learning with repeated stimulation after partial and total cortical blindness

Lesions of occipital cortex result in loss of sight in the corresponding regions of visual fields. The traditional view that, apart from some spontaneous recovery in the acute phase, field defects remain permanently and irreversibly blind, has been challenged. In patients with partial field loss, a range of residual visual abilities in the absence of conscious perception (blindsight) has been demonstrated (Weiskrantz, 1986). Recent findings (Sahraie et al., 2006, 2010) have also demonstrated increased visual sensitivity in the field defect following repeated stimulation. We aimed to extend these findings by systematically exploring whether repeated stimulation can also lead to increased visual sensitivity in two cases with total (bilateral) cortical blindness. In addition, for a case of partial blindness, we examined the extent of the recovery as a function of stimulated region of the visual field, over extended periods of visual training. Positive auditory feedback was provided during the training task for correct detection of a spatial grating pattern presented at specific retinotopic locations using a temporal two alternative forced-choice paradigm (Neuro-Eye Therapy). All three cases showed improved visual sensitivity with repeated stimulation. The findings indicate that perceptual learning can occur through systematic visual field stimulation even in cases of bilateral cortical blindness.     

The use of self-talk during elite cricket batting performance

ObjectiveThe purpose of this study was to qualitatively investigate the use of self-talk during cricket batting performance through an innovative approach that allowed for within performance responses to be examined.Design and methodFive elite cricketers were interviewed alongside edited video footage of their batting innings. Semi-structured interviews were conducted to gather in-depth information and explanations about the participants' use of self-talk during each critical incident.Results and conclusionsThe findings of this study highlighted the use of instructional and motivational self-talk as a fluctuating continual narrative that enhanced skill execution, self-efficacy and focus of attention, whilst reducing performance anxiety. In particular, the athletes described the effectiveness of self-determined self-talk on their performance. Specifically, they advocated self-talk that narrowed their attentional focus and redirected their thoughts to performance-related cues during periods of declining performance.     

Learning influences the encoding of static and dynamic faces and their recognition across different spatial frequencies

Studies on face recognition have shown that observers are faster and more accurate at recognizing faces learned from dynamic sequences than those learned from static snapshots. Here, we investigated whether different learning procedures mediate the advantage for dynamic faces across different spatial frequencies. Observers learned two faces—one dynamic and one static—either in depth (Experiment 1) or using a more superficial learning procedure (Experiment 2). They had to search for the target faces in a subsequent visual search task. We used high-spatial frequency (HSF) and low-spatial frequency (LSF) filtered static faces during visual search to investigate whether the behavioural difference is based on encoding of different visual information for dynamically and statically learned faces. Such encoding differences may mediate the recognition of target faces in different spatial frequencies, as HSF may mediate featural face processing whereas LSF mediates configural processing. Our results show that the nature of the learning procedure alters how observers encode dynamic and static faces, and how they recognize those learned faces across different spatial frequencies. That is, these results point to a flexible usage of spatial frequencies tuned to the recognition task.     

Age Effects on Visual-Perceptual Processing and Confrontation Naming*

ABSTRACT

The impact of age-related changes in visual-perceptual processing on naming ability has not been reported. The present study investigated the effects of 6 levels of spatial frequency and 6 levels of contrast on accuracy and latency to name objects in 14 young and 13 older neurologically normal adults with intact lexical-semantic functioning. Spatial frequency and contrast manipulations were made independently. Consistent with the hypotheses, variations in these two visual parameters impact naming ability in young and older subjects differently. The results from the spatial frequency-manipulations revealed that, in general, young vs. older subjects are faster and more accurate to name. However, this age-related difference is dependent on the spatial frequency on the image; differences were only seen for images presented at low (e.g., 0.25–1 c/deg) or high (e.g., 8–16 c/deg) spatial frequencies. Contrary to predictions, the results from the contrast manipulations revealed that overall older vs. young adults are more accurate to name. Again, however, differences were only seen for images presented at the lower levels of contrast (i.e., 1.25%). Both age groups had shorter latencies on the second exposure of the contrast-manipulated images, but this possible advantage of exposure was not seen for spatial frequency. Category analyses conducted on the data from this study indicate that older vs. young adults exhibit a stronger nonliving-object advantage for naming spatial frequency-manipulated images. Moreover, the findings suggest that bottom-up visual-perceptual variables integrate with top-down category information in different ways. Potential implications on the aging and naming (and recognition) literature are discussed.     

Distributional analyses in the picture–word interference paradigm: Exploring the semantic interference and the distractor frequency effects

The present study explores the distributional features of two important effects within the picture–word interference paradigm: the semantic interference and the distractor frequency effects. These two effects display different and specific distributional profiles. Semantic interference appears greatly reduced in faster response times, while it reaches its full magnitude only in slower responses. This can be interpreted as a sign of fluctuant attentional efficiency in resolving response conflict. In contrast, the distractor frequency effect is mediated mainly by a distributional shift, with low-frequency distractors uniformly shifting reaction time distribution towards a slower range of latencies. This finding fits with the idea that distractor frequency exerts its effect by modulating the point in time in which operations required to discard the distractor can start. Taken together, these results are congruent with current theoretical accounts of both the semantic interference and distractor frequency effects. Critically, distributional analyses highlight and further describe the different cognitive dynamics underlying these two effects, suggesting that this analytical tool is able to offer important insights about lexical access during speech production.     

Age of acquisition's effect on memory for semantically associated word pairs

This experiment investigated the effects of age of acquisition (AoA) in memory for associated word pairs in a cued recall task. Participants studied a list of frequency-controlled early- and late-acquired words in semantically related pairs and then were asked to recall the second word of the pair when cued with the first. Reaction time effects were found, showing that a late-acquired cue for an early-acquired target word was responded to significantly faster than other combinations. Additionally, late-acquired target words resulted in significantly more accurate responses. As significant differences were found even when frequency was controlled, the effects must therefore stem from the manipulations of AoA. Given this evidence, the implications for AoA's effects on the organization of semantic memory are explored.     

Perceptual simulations and linguistic representations have differential effects on speeded relatedness judgements and recognition memory

We examined the effect of spatial iconicity (a perceptual simulation of canonical locations of objects) and word-order frequency on language processing and episodic memory of orientation. Participants made speeded relatedness judgements to pairs of words presented in locations typical of their real-world arrangements (e.g., ceiling on top and floor on bottom). They then engaged in a surprise orientation recognition task for the word pairs. We replicated Louwerse's (2008) Louwerse, M. M. 2008. Embodied representations are encoded in language. Psychonomic Bulletin & Review, 15: 838–844. [Crossref], [PubMed], [Web of Science ®] , [Google Scholar] finding that word-order frequency has a stronger effect on semantic relatedness judgements than does spatial iconicity. This is consistent with recent suggestions that linguistic representations have a stronger impact on immediate decisions about verbal materials than do perceptual simulations. In contrast, spatial iconicity enhanced episodic memory of orientation to a greater extent than word-order frequency did. This new finding indicates that perceptual simulations have an important role in episodic memory. Results are discussed with respect to theories of perceptual representation and linguistic processing.     

Do the effects of subjective frequency and age of acquisition survive better word frequency norms?

Megastudies with processing efficiency measures for thousands of words allow researchers to assess the quality of the word features they are using. In this article, we analyse reading aloud and lexical decision reaction times and accuracy rates for 2,336 words to assess the influence of subjective frequency and age of acquisition on performance. Specifically, we compare newly presented word frequency measures with the existing frequency norms of Ku?era and Francis (1967) Ku?era, H. and Francis, W. 1967. Computational analysis of present-day American English, Providence, RI: Brown University Press.  [Google Scholar], HAL (Burgess & Livesay, 1998 Burgess, C. and Livesay, K. 1998. The effect of corpus size in predicting reaction time in a basic word recognition task: Moving on from Kucera and Francis. Behavior Research Methods, Instruments, & Computers, 30: 272–277. [Crossref] , [Google Scholar]), Brysbaert and New (2009) Brysbaert, M. and New, B. 2009. Moving beyond Kucera and Francis: A critical evaluation of current word frequency norms and the introduction of a new and improved word frequency measure for American English. Behavior Research Methods, 41: 977–990. [Crossref], [PubMed], [Web of Science ®] , [Google Scholar], and Zeno, Ivens, Millard, and Duvvuri (1995) Zeno, S. M., Ivens, S. H., Millard, R. T. and Duvvuri, R. 1995. The educator's word frequency guide, Brewster, NY: Touchstone Applied Science.  [Google Scholar]. We show that the use of the Ku?era and Francis word frequency measure accounts for much less variance than the other word frequencies, which leaves more variance to be “explained” by familiarity ratings and age-of-acquisition ratings. We argue that subjective frequency ratings are no longer needed if researchers have good objective word frequency counts. The effect of age of acquisition remains significant and has an effect size that is of practical relevance, although it is substantially smaller than that of the first phoneme in naming and the objective word frequency in lexical decision. Thus, our results suggest that models of word processing need to utilize these recently developed frequency estimates during training or setting baseline activation levels in the lexicon.     

副中央凹低频双字词首字字频的预视效应研究

为探讨副中央凹字的加工负荷在预视加工中的作用,选择高、低首字字频的低频双字词作为副中央凹目标词,同时采用边界范式操纵目标词首字的预视类型（包括目标预视和假字预视）。使用眼动仪记录读者的阅读过程。结果在目标词首字与整词上均发现了显著的预视效应,目标预视下的注视时间显著短于假字预视下的注视时间;在目标词的凝视时间和总注视时间上,字频主效应显著,首字低频条件下的注视时间显著长于首字高频条件;但没有发现两因素的交互作用。结果表明副中央凹低频双字词首字字频并不影响预视效应的大小。     

Effects of pair collaboration and word-frequency in recognition memory: a study with the remember-know procedure

The present study investigated the effects of pair collaboration and word-frequency on recognition memory, using the "remember-know" procedure. The aim was to test the predictions of the information-exchange hypothesis (Clark, Hori, Putnam & Martin, 2000), which states that collaborative facilitation occurs when participants are able to share their recollective memories with other members of the group. Results showed that recognition performance was significantly better in the collaborative than in the individual condition, and better for low-frequency than for high-frequency words. The advantage of collaborating dyads was produced by an increase of correct hits, coupled with a significant reduction of false alarms. Furthermore, the analysis of the "remember" (R) and "know" (K) responses indicated that the effects of both pair collaboration and word-frequency were larger on recollection than on familiarity processes. It is concluded that, in a collaborative condition, arguments based on the retrieval of the contextual details associated with the target words are more effective than those based on familiarity in increasing the proportions of correct hits. In addition, it is proposed that collaboration may lead to a reduction of the probability to accept new items on the basis of familiarity (K) responses.