1,721,027 research outputs found
Unconventionally trendy: The pluralistic endeavour of Cortex into the human cognitive neurosciences
No full textThis viewpoint summarizes conversations between three generations of cognitive neuropsychologists about Cortex's contributions to our understanding of human cognition. We structured our conversation along a historical timeline and focused on selected key topics, that we also contributed to. Beginning with the advent of neuropsychology, and its focus on language disorders and hemispheric lateralisation, we quickly moved to the birth of Cortex in the 1960s pausing our conversion on spatial cognition and the critical window offered by unilateral neglect on its representational understanding. Realising that as time went by, the initial focus on impaired cognition expanded towards healthy individuals too, we noticed it coincided with the emergence of sophisticated imaging methods, and with them, the possibility to better draw the functional architecture of the brain across all known cognitive domains. In parallel, research on neuropsychological disorders had to include those implied by ageing, which rapidly became a critical topic due to the impressive increase of older individuals in Western societies. With the massive availability of data and shared information in the last decades, we observed a rise in open science practices and identified a clear future, yet to be fully unclosed, for a re-definition of neuropsychological profiles through big data in what is labelled as precision psychology. Across this journey, Cortex stood up for its unconventionally trendy, pluralistic and unbiased approach, which we hope will continue to be faithful to those core elements that are necessary to explain human cognition, which is, undoubtedly, among the most complex scientific subjects to tackl
The upside of cumulative conceptual interference on exemplar-level mnemonic discrimination.
Full text linkpeer reviewedAlthough long-term visual memory (LTVM) has a remarkable capacity, the fidelity of its episodic representations can be influenced by at least two intertwined interference mechanisms during the encoding of objects belonging to the same category: the capacity to hold similar episodic traces (e.g., different birds) and the conceptual similarity of the encoded traces (e.g., a sparrow shares more features with a robin than with a penguin). The precision of episodic traces can be tested by having participants discriminate lures (unseen objects) from targets (seen objects) representing different exemplars of the same concept (e.g., two visually similar penguins), which generates interference at retrieval that can be solved if efficient pattern separation happened during encoding. The present study examines the impact of within-category encoding interference on the fidelity of mnemonic object representations, by manipulating an index of cumulative conceptual interference that represents the concurrent impact of capacity and similarity. The precision of mnemonic discrimination was further assessed by measuring the impact of visual similarity between targets and lures in a recognition task. Our results show a significant decrement in the correct identification of targets for increasing interference. Correct rejections of lures were also negatively impacted by cumulative interference as well as by the visual similarity with the target. Most interestingly though, mnemonic discrimination for targets presented with a visually similar lure was more difficult when objects were encoded under lower, not higher, interference. These findings counter a simply additive impact of interference on the fidelity of object representations providing a finer-grained, multi-factorial, understanding of interference in LTVM
Age-related differences during visual search: the role of contextual expectations and cognitive control mechanisms
No full textDuring the visual search, cognitive control mechanisms activate to inhibit distracting information and efficiently orient attention
towards contextually relevant regions likely to contain the search target. Cognitive ageing is known to hinder cognitive control
mechanisms, however little is known about their interplay with contextual expectations, and their role in visual search. In two eyetracking experiments, we compared the performance of a younger and an older group of participants searching for a target object varying in semantic consistency with the search scene (e.g., a basket of bread vs. a clothes iron in a restaurant scene) after
being primed with contextual information either congruent or incongruent with it (e.g., a restaurant vs. a bathroom). Primes were administered either as scenes (Experiment 1) or words (Experiment 2, which included scrambled words as neutral primes). Participants also completed two inhibition tasks (Stroop and Flanker) to assess their cognitive control. Older adults had greater difficulty than younger adults when searching for inconsistent objects, especially when primed with congruent information (Experiment 1), or a scrambled word (neutral condition, Experiment 2). When the target object violates the semantics of the search context, congruent expectations or perceptual distractors, have to be suppressed through cognitive control, as they are irrelevant to the search. In fact, higher cognitive control, especially in older participants, was associated with better target detection in these more challenging conditions, although it did not influence eye-movement responses. These results shed new light on the links between cognitive control, contextual expectations and visual attention in healthy ageing
Differential effects of intrinsic properties of natural scenes and interference mechanisms on recognition processes in long-term visual memory
No full textHumans display remarkable long-term visual memory (LTVM) processes. Even though images may be intrinsically memorable, the fidelity of their visual representations, and consequently the likelihood of successfully retrieving them, hinges on their similarity when concurrently held in LTVM. In this debate, it is still unclear whether intrinsic features of images (perceptual and semantic) may be mediated by mechanisms of interference generated at encoding, or during retrieval, and how these factors impinge on recognition processes. In the current study, participants (32) studied a stream of 120 natural scenes from 8 semantic categories, which varied in frequencies (4, 8, 16 or 32 exemplars per category) to generate different levels of category interference, in preparation for a recognition test. Then they were asked to indicate which of two images, presented side by side (i.e. two-alternative forced-choice), they remembered. The two images belonged to the same semantic category but varied in their perceptual similarity (similar or dissimilar). Participants also expressed their confidence (sure/not sure) about their recognition response, enabling us to tap into their metacognitive efficacy (meta-d'). Additionally, we extracted the activation of perceptual and semantic features in images (i.e. their informational richness) through deep neural network modelling and examined their impact on recognition processes. Corroborating previous literature, we found that category interference and perceptual similarity negatively impact recognition processes, as well as response times and metacognitive efficacy. Moreover, images semantically rich were less likely remembered, an effect that trumped a positive memorability boost coming from perceptual information. Critically, we did not observe any significant interaction between intrinsic features of images and interference generated either at encoding or during retrieval. All in all, our study calls for a more integrative understanding of the representational dynamics during encoding and recognition enabling us to form, maintain and access visual information
Similar mechanisms of temporary bindings for identity and location of objects in healthy ageing: An eye-tracking study with naturalistic scenes
No full textThe ability to maintain visual working memory (VWM) associations about the identity and location
of objects has at times been found to decrease with age. To date, however, this age-related difficulty
was mostly observed in artificial visual contexts (e.g., object arrays), and so it is unclear whether it
may manifest in naturalistic contexts, and in which ways. In this eye-tracking study, 26 younger and
24 healthy older adults were asked to detect changes in a critical object situated in a photographic
scene (192 in total), about its identity (the object becomes a different object but maintains the same
position), location (the object only changes position) or both (the object changes in location and
identity). Aging was associated with a lower change detection performance. A change in identity was
harder to detect than a location change, and performance was best when both features changed,
especially in younger adults. Eye movements displayed minor differences between age groups (e.g.,
shorter saccades in older adults) but were similarly modulated by the type of change. Latencies to the
first fixation were longer and the amplitude of incoming saccades was larger when the critical object
changed in location. Once fixated, the target object was inspected for longer when it only changed
in identity compared to location. Visually salient objects were fixated earlier, but saliency did not
affect any other eye movement measures considered, nor did it interact with the type of change.
Our findings suggest that even though aging results in lower performance, it does not selectively
disrupt temporary bindings of object identity, location, or their association in VWM, and highlight
the importance of using naturalistic contexts to discriminate the cognitive processes that undergo
detriment from those that are instead spared by aging
Unidimensional and multidimensional methods for recurrence quantification analysis with crqa
Full text linkRecurrence quantification analysis is a widely used method for characterizing patterns in
time series. This article presents a comprehensive survey for conducting a wide range of recurrencebased
analyses to quantify the dynamical structure of single and multivariate time series and capture
coupling properties underlying leader-follower relationships. The basics of recurrence quantification
analysis (RQA) and all its variants are formally introduced step-by-step from the simplest autorecurrence
to the most advanced multivariate case. Importantly, we show how such RQA methods can
be deployed under a single computational framework in R using a substantially renewed version of
our crqa 2.0 package. This package includes implementations of several recent advances in recurrencebased
analysis, among them applications to multivariate data and improved entropy calculations
for categorical data. We show concrete applications of our package to example data, together with a
detailed description of its functions and some guidelines on their usage
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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