Modeling age-related differences in immediate memory using SIMPLE

In the SIMPLE model (Scale Invariant Memory and Perceptual Learning), performance on memory tasks is determined by the locations of items in multidimensional space, and better performance is associated with having fewer close neighbors. Unlike most previous simulations with SIMPLE, the ones reported here used measured, rather than assumed, dimensional values. The data to be modeled come from an experiment in which younger and older adults recalled lists of acoustically confusable and nonconfusable items. A multidimensional scaling solution based on the memory confusions was obtained. SIMPLE accounted for the overall difference in performance both between the two age groups and, within each age group, the overall difference between acoustically confusable and nonconfusable items in terms of the MDS coordinates. Moreover, the model accounted for the serial position functions and error gradients. Finally, the generality of the model’s account was examined by fitting data from an already published study. The data and the modeling support the hypothesis that older adults’ memory may be worse, in part, because of altered representations due to age-related auditory perceptual deficits

Asymmetric spatial processing under cognitive load

Spatial attention allows us to selectively process information within a certain location in space. Despite the vast literature on spatial attention, the effect of cognitive load on spatial processing is still not fully understood. In this study we added cognitive load to a spatial processing task, so as to see whether it would differentially impact upon the processing of visual information in the left versus the right hemispace. The main paradigm consisted of a detection task that was performed during the maintenance interval of a verbal working memory task. We found that increasing cognitive working memory load had a more negative impact on detecting targets presented on the left side compared to those on the right side. The strength of the load effect correlated with the strength of the interaction on an individual level. The implications of an asymmetric attentional bias with a relative disadvantage for the left (vs the right) hemispace under high verbal working memory (WM) load are discussed

On what we experience when we hear people speak

According to perceptualism, fluent comprehension of speech is a perceptual achievement, in as much as it is akin to such high-level perceptual states as the perception of objects as cups or trees, or of people as happy or sad. According to liberalism, grasp of meaning is partially constitutive of the phenomenology of fluent comprehension. I here defend an influential line of argument for liberal perceptualism, resting on phenomenal contrasts in our comprehension of speech, due to Susanna Siegel and Tim Bayne, against objections from Casey O'Callaghan and Indrek Reiland. I concentrate on the contrast between the putative immediacy of meaning-assignment in fluent comprehension, as compared with other, less ordinary, perhaps translation-based ways of getting at the meaning of speech. I argue this putative immediacy is difficult to capture on a non-perceptual view (whether liberal or non-liberal), and that the immediacy in question has much in common with that which applies in other, less controversial cases of high-level perception

Phonetic categorisation and cue weighting in adolescents with Specific Language Impairment (SLI)

This study investigates phonetic categorisation and cue weighting in adolescents and young adults with Specific Language Impairment (SLI). We manipulated two acoustic cues, vowel duration and F1 offset frequency, that signal word-final stop consonant voicing ([t] and [d]) in English. Ten individuals with SLI (14.0–21.4 years), 10 age-matched controls (CA; 14.6–21.9 years) and 10 non-matched adult controls (23.3–36.0 years) labelled synthetic CVC non-words in an identification task. The results showed that the adolescents and young adults with SLI were less consistent than controls in the identification of the good category representatives. The group with SLI also assigned less weight to vowel duration than the adult controls. However, no direct relationship between phonetic categorisation, cue weighting and language skills was found. These findings indicate that some individuals with SLI have speech perception deficits but they are not necessarily associated with oral language skills

A tutorial on cue combination and Signal Detection Theory: Using changes in sensitivity to evaluate how observers integrate sensory information

Many sensory inputs contain multiple sources of information (‘cues’), such as two sounds of different frequencies, or a voice heard in unison with moving lips. Often, each cue provides a separate estimate of the same physical attribute, such as the size or location of an object. An ideal observer can exploit such redundant sensory information to improve the accuracy of their perceptual judgments. For example, if each cue is modeled as an independent, Gaussian, random variable, then combining Ncues should provide up to a √N improvement in detection/discrimination sensitivity. Alternatively, a less efficient observer may base their decision on only a subset of the available information, and so gain little or no benefit from having access to multiple sources of information. Here we use Signal Detection Theory to formulate and compare various models of cue-combination, many of which are commonly used to explain empirical data. We alert the reader to the key assumptions inherent in each model, and provide formulas for deriving quantitative predictions. Code is also provided for simulating each model, allowing expected levels of measurement error to be quantified. Based on these results, it is shown that predicted sensitivity often differs surprisingly little between qualitatively distinct models of combination. This means that sensitivity alone is not sufficient for understanding decision efficiency, and the implications of this are discussed

Absolute identification by relative judgment

In unidimensional absolute identification tasks, participants identify stimuli that vary along a single dimension. Performance is surprisingly poor compared with discrimination of the same stimuli. Existing models assume that identification is achieved using long-term representations of absolute magnitudes. The authors propose an alternative relative judgment model (RJM) in which the elemental perceptual units are representations of the differences between current and previous stimuli. These differences are used, together with the previous feedback, to respond. Without using long-term representations of absolute magnitudes, the RJM accounts for (a) information transmission limits, (b) bowed serial position effects, and (c) sequential effects, where responses are biased toward immediately preceding stimuli but away from more distant stimuli (assimilation and contrast)

Memory for sounds: novel technological solutions for the evaluation of mnestic skills

Working memory (WM) plays a crucial role in helping individuals to perform everyday activities. The neural structures underlying this system continue to develop during infancy and reach maturity only late in development. Despite useful insights into visual memory mechanisms, audio-spatial memory has not been thoroughly investigated, especially in children and congenitally blind individuals. The main scientific objective of this thesis was to increase knowledge of spatial WM and imagery abilities in the auditory modality. We focused on how these skills change during typical development and on the consequences of early visual deprivation. Our first hypothesis was that the changes in WM functionality and spatial skills occurring in the early years of life, influence the ability to remember and associate spatialized sounds or to explore and learn acoustic spatial layouts. Since vision plays a crucial role in spatial cognition (ThinusBlanc and Gaunet, 1997), we expected blind individuals to encounter specific difficulties when asked to process and manipulate spatial information retained in memory, as already observed in the haptic modality (Cattaneo et al., 2008; Vecchi, 1998). Although some studies demonstrated the superior performance of the blind in various verbal-memory tasks (Amedi et al., 2003; Po\u17e\ue1r, 1982; R\uf6der et al., 2001), very little is known on how they remember and manipulate acoustic spatial information. The investigation of auditory cognition often requires specially adapted hardware and software solutions rarely available on the market. For example, in the case of studying cognitive functions that involve auditory spatial information, multiple acoustic spatial locations are required, such as numerous speakers or dedicated virtual acoustics. Thus, to the aim of this thesis, we took advantage of novel technological solutions developed explicitly for delivering non-visual spatialized stimuli. We worked on the software development of a vertical array of speakers (ARENA2D), an audio-tactile tablet (Audiobrush), and we designed a system based on an acoustic virtual reality (VR) simulation. These novel solutions were used to adapt validated clinical procedures (Corsi-Block test) and games (the card game Memory) to the auditory domain, to be also performed by visually impaired individuals. Thanks to the technologies developed in these years, we could investigate these topics and observed that audio-spatial memory abilities are strongly affected by the developmental stage and the lack of visual experience

Musical expertise and the ability to imagine loudness

Most perceived parameters of sound (e.g. pitch, duration, timbre) can also be imagined in the absence of sound. These parameters are imagined more veridically by expert musicians than non-experts. Evidence for whether loudness is imagined, however, is conflicting. In music, the question of whether loudness is imagined is particularly relevant due to its role as a principal parameter of performance expression. This study addressed the hypothesis that the veridicality of imagined loudness improves with increasing musical expertise. Experts, novices and non-musicians imagined short passages of well-known classical music under two counterbalanced conditions: 1) while adjusting a slider to indicate imagined loudness of the music and 2) while tapping out the rhythm to indicate imagined timing. Subtests assessed music listening abilities and working memory span to determine whether these factors, also hypothesised to improve with increasing musical expertise, could account for imagery task performance. Similarity between each participant's imagined and listening loudness profiles and reference recording intensity profiles was assessed using time series analysis and dynamic time warping. The results suggest a widespread ability to imagine the loudness of familiar music. The veridicality of imagined loudness tended to be greatest for the expert musicians, supporting the predicted relationship between musical expertise and musical imagery ability

Visual search in ecological and non-ecological displays: Evidence for a non-monotonic effect of complexity on performance

Copyright @ 2013 PLoSThis article has been made available through the Brunel Open Access Publishing Fund.Considerable research has been carried out on visual search, with single or multiple targets. However, most studies have used artificial stimuli with low ecological validity. In addition, little is known about the effects of target complexity and expertise in visual search. Here, we investigate visual search in three conditions of complexity (detecting a king, detecting a check, and detecting a checkmate) with chess players of two levels of expertise (novices and club players). Results show that the influence of target complexity depends on level of structure of the visual display. Different functional relationships were found between artificial (random chess positions) and ecologically valid (game positions) stimuli: With artificial, but not with ecologically valid stimuli, a “pop out” effect was present when a target was visually more complex than distractors but could be captured by a memory chunk. This suggests that caution should be exercised when generalising from experiments using artificial stimuli with low ecological validity to real-life stimuli.This study is funded by Brunel University and the article is made available through the Brunel Open Access Publishing Fund

Musicians have better memory than nonmusicians: A meta-analysis

Background Several studies have found that musicians perform better than nonmusicians in memory tasks, but this is not always the case, and the strength of this apparent advantage is unknown. Here, we conducted a meta-analysis with the aim of clarifying whether musicians perform better than nonmusicians in memory tasks. Methods Education Source; PEP (WEB)\u2014Psychoanalytic Electronic Publishing; Psychology and Behavioral Science (EBSCO); PsycINFO (Ovid); PubMed; ScienceDirect\u2014AllBooks Content (Elsevier API); SCOPUS (Elsevier API); SocINDEX with Full Text (EBSCO) and Google Scholar were searched for eligible studies. The selected studies involved two groups of participants: young adult musicians and nonmusicians. All the studies included memory tasks (loading long-term, short-term or working memory) that contained tonal, verbal or visuospatial stimuli. Three meta-analyses were run separately for long-term memory, short-term memory and working memory. Results We collected 29 studies, including 53 memory tasks. The results showed that musicians performed better than nonmusicians in terms of long-term memory, g = .29, 95% CI (.08\u2013.51), short-term memory, g = .57, 95% CI (.41\u2013.73), and working memory, g = .56, 95% CI (.33\u2013.80). To further explore the data, we included a moderator (the type of stimulus presented, i.e., tonal, verbal or visuospatial), which was found to influence the effect size for short-term and working memory, but not for long-term memory. In terms of short-term and working memory, the musicians\u2019 advantage was large with tonal stimuli, moderate with verbal stimuli, and small or null with visuospatial stimuli. Conclusions The three meta-analyses revealed a small effect size for long-term memory, and a medium effect size for short-term and working memory, suggesting that musicians perform better than nonmusicians in memory tasks. Moreover, the effect of the moderator suggested that, the type of stimuli influences this advantage