Abstracts - Center for Visual Cognition

Transcription

Abstracts - Center for Visual Cognition
Abstracts
“EEG Data Analyses in Cognitive Science”
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December 15 – 19 , 2014
Center for Visual Cognition, Department of Psychology, University of Copenhagen
André Haese & Daniela Czernochowski
Cognitive Science, University of Kaiserslautern
Abstract: Two processes contribute to episodic memory retrieval. By comparing ERPs, familiarity
— related to an early frontal positivity underlying an intuitive old-new decision — can be
dissociated from recollection – a later parietal positivity associated with confident judgments based
on the retrieval of contextual information. Behavioral studies suggest children rely on familiarity, but
no corresponding ERP effects were observed (unless children are urged to respond fast); instead a
parietal positivity suggests recollection is used predominantly. Here, children and young adults
decided if items were more commonly found indoors or outdoors. During retrieval, participants
categorized items as perceptually “identical”, perceptually “changed” or “new”. Afterwards,
participants repeated the task, this time memorizing the items. Across groups, performance was
better after intentional encoding and for identical exemplars. ERP analyses revealed that in
younger children, only parietal old/new effects were observed, whereas adults employed familiarity
and recollection. In older children, we observed early old/new effects after intentional encoding,
whereas the later effect was broadly distributed, resembling adults’ distribution. Thus our data
suggest that children and adults differentially use the two retrieval processes: Despite comparable
behavioral performance, only young adults seem to use familiarity, whereas recollection was
observed across all age groups.
Kathrin C. J. Eschmann
Experimental Neuropsychology Unit, Saarland University
Abstract: Neurofeedback Training and its Transfer to Cognitive and Memory Control
Abilities.
Memory enhancement is not only a problem of a gradually aging society, but also of a young
achievement-oriented society. Interestingly, cognitive control training studies demonstrate
remarkable capacity for plasticity of the adult brain. According to the overlap hypothesis,
successful transfer from a trained to an untrained task occurs if both tasks (1) engage the same
processing mechanisms and (2) activate similar brain regions. Moreover, this common brain
substrate needs to change as a function of training. Thus, it seems conceivable to directly modify
the assumed neural activity underlying both tasks by means of neurofeedback. The aim of the
present study is to train control processes of source memory retrieval and their underlying neuronal
activity by enhancing task-specific theta oscillations via neurofeedback training. Additionally,
transfer effects from neurofeedback training to other cognitive control abilities, such as working
memory maintenance and interference resolution, will be explored. By this, the present project
aims at extending the overlap hypothesis from functional and anatomical overlap to overlap of EEG
dynamics. If episodic memory performance can be enhanced effectively by neurofeedback, the
present study would disclose a mechanism for memory enhancement in young adults with
potentially high relevance for treatment of memory decline in old age.
Thomas Ousterhout
Center for Language Technology, University of Copenhagen
Abstract: EEG responses to simultaneous non-redundant multimodal communication.
Semantic priming is an effect that occurs when a response to a subsequent stimulus, called a
probe, is faster if semantically related to a preceding stimulus, called a prime.
Some semantic priming experiments have used cross-form semantic processing, meaning using
different types of stimuli, such as combinations of picture and words. Others used cross modal
stimuli showing that both pair orders of sounds and visually displayed words produced similar
faster response times to related versus unrelated stimulus pairs. Mixing the sensory stimuli had no
different effect on the behavioral response of the semantic priming showing that various
combinations of verbal/non-verbal/auditory/visual pairs produce the same semantic priming effect.
With multimodal integration during object recognition tasks, subjects had to identify one of two
objects using auditory stimuli, visual stimuli, or both as quickly as possible. Subjects were faster
and more accurate with multimodal identification than unimodal showing that there was some kind
of facilitation involved in the integration of both stimuli. I will be using non-redundant simultaneous
stimuli (audio and visual) to see if there is a facilitation effect when both stimuli are required to
produce a correct response.
David Morris
Department of Nordic Studies and Linguistics, University of Copenhagen
Abstract: My research focuses on cortical event-related potentials in response to acoustic,
particularly speech, stimuli. More specifically, I am interested in the coding of speech in devices
that are used to transform acoustic stimuli and deliver it to a recipient across an electrical-neural
interface. These devices, called cochlear implants, use radio frequency transmission to achieve
transcutaneous communication between an external processor and an array of implanted
stimulating electrodes. When picked up via EEG, this radio frequency transmission is seen as a
large artifact that continually mars the neural response throughout stimulus presentation. One
strategy to deal with this artifact has been to use stimuli of short duration (<30 milliseconds) so that
the cortical response occurs after stimulus presentation. The disadvantage of this strategy is that
longer events in the acoustic speech stream cannot be used as stimuli. This talk will outline other
methods from the literature that have been used in the separation of artifact from neural
response. These include principal component analysis, independent component analysis and
spatial cancellation, all of which are techniques that I hope to learn more about during the course.
Dalia Bagdziunaite
Center for Decision Neuroscience, Copenhagen Business School
Abstract: Compulsive buying disorder (CBD) is a repetitive chronic purchasing behavior
overwhelming the urges, which has negative consequences to the person suffering and as well to
the society (Black, 2007; Manolis & Roberts, 2008; Lejoyeux & Weinstein, 2010). CBD is
associated with impulse control disorder, the enhanced need for emotional stimulation and
aberrant relationship between emotional responses and choices. However, little is still known about
the actual psychological and physiological mechanisms underlying the phenomenon. By comparing
subjects with CBD to a control group, during the eye---­‐tracking study, we found that CBD is not
associated with lower performance on executive function or stronger emotional responses. Rather,
an observed increase in willingness to pay (WTP) specifically for fashion products was associated
with emotional response in CBD subjects compared to healthy subjects. By this token, products of
interest (e.g. fashion items) produce bottom---­‐up emotional responses that skew the decision---­‐
making process, leading CBD sufferers to make bad purchase decisions. The reported findings
provide new insights into the classification and understanding the neurobiological and
neurophysiological underpinning of the CBD. However, more research is needed to understand the
visual and neurobiological information to explore several questions: (1) To test whether these
results are valid in the ecological choice situations in the stores (2) To understand, where exactly
during the value---­‐based decision---­‐ making process the emotions impact the choices. To
investigate the above mentioned issues, portable neuroscientific tools such as mobile eye---­‐
tracking – Tobii Glasses, running at 30 Hz, combined with Mobile EEG – 10 channel ABM---­‐X,
measuring emotional engagement, cognitive load, and motivation will be employed to test the
effects in three manipulative in---­‐store conditions.
Violaine Michel Lange
PROGRAM - Information Prominence and Grammar in the Mind and Brain, University of
Copenhagen
Abstract: The present study builds on the dynamics underlying single-word (1W) encoding for
production issued from previous ERP investigation and extends it to the production of two-word
(2W) adjective-noun phrases (NP). Our experiment compared the NPs elicited with standard (1W)
and coloured (2W) line drawings. Naming latencies were 53 ms longer for the production of 2W
relative to 1W. Converging results from waveform and topographic analyses carried out on
stimulus- and response-aligned ERPs indicated that the two conditions diverged in a late timewindow, where a longer lasting stable topographic pattern appeared for 2W relative to 1W between
300 and respectively 450 and 480 ms following picture presentation. This time window has been
associated with phonological encoding in single word planning, thus suggesting that the cost of
planning the second word is reflected during phonological encoding processes of the first word.
These results are discussed in light of single and multi-word production models.
Tobias Feldmann-Wüstefeld
Department of Experimental and Biological Psychology, University of Marburg
Abstract: The PD and NT component as indicators of attentional suppression and
prioritization in homogenous and heterogeneous visual contexts. Context homogeneity has
been identified as one factor that determines efficiency in visual search tasks. It has been argued
that pre-attentive grouping may account for accelerated search because it allowed for processing
of larger perceptual units. As a result the target may be prioritized more easily. However, visual
search efficiency generally depends on both prioritization of relevant and suppression of irrelevant
information. In the present study it was investigated whether grouping does not only enhance
prioritization of relevant, but also suppression of irrelevant information. Prioritization of targets and
concurrent suppression of salient distractors was disentangled by using subcomponents of the
attention-indicating N2pc in the ERP. The target-elicited NT component showed faster and more
pronounced attention allocation for targets in homogeneous than in heterogeneous contexts. The
distractor-elicited PD showed delayed distractor suppression in heterogeneous contexts and
attentional capture by the distractor in heterogeneous, but not in homogeneous contexts. Thus the
present results show that pre-attentive grouping facilitates target processing and distractor
suppression and suggest that goal-oriented processing is less vulnerable to interferences from
potentially distracting low-level features in homogeneous contexts.
Jens Madsen
DTU Compute, Technical University of Denmark
Abstract: Why do people listen to music? The regulation of people's mood and current emotional
state has been found as a key factor in people's music consumption. Evidence shows that
matching the emotions expressed in music with the current emotional state of the user leads to a
range of cognitive benefits.
This talk will focus on the one side of this affect-matching task, namely how do we find out what
emotions are expressed in music? And can we create predictive models of this to easy the scope
of elicitation? In creating such models a typical approach is to look at three different aspects, first,
self-reported annotations (rankings, ratings, comparisons, tags, etc.) for quantifying the expressed
emotions in music, given a particular emotional model. Secondly, finding a suitable audio
representation (using audio or lyrical features), and finally associating the two aspects using
machine learning methods with the aim to create predictive models of the annotations describing
the higher level cognitive aspect in music.
Méadhbh Brosnan
TCD Institute of Neuroscience, Trinity College Dublin
Abstract: Enhancing plasticity in older adults via tDCS. This study focuses on the potential of
brain stimulation to enhance attention in ageing. Evidence from neuroimaging studies,
psychophysical studies using lateralised stimuli, and patients with focal right hemisphere lesions
suggests there is a right-lateralised network underlying the ability to sustain attention. The right
DLPFC appears to be a crucial node in this network, and previous research has shown that brain
stimulation of the right prefrontal cortex leads to superior error awareness in older adults (Harty et
al., 2014). Older adults’ ability to signal their errors is also correlated with sustained attention
capacity (Harty et al., 2013), setting a precedent for examining the effects of brain stimulation on
both sustained attention and error awareness. I aim to establish whether Right Prefrontal Anodal
Transcranial Direct Current Stimulation (tDCS) leads to improvements in sustained attention and
awareness in older adults who are cognitively healthy. Mechanistic changes in neural activity
during stimulation are assessed using simultaneous tDCS-EEG, and changes in arousal are
measured using the Skin Conductance Response.
Louise Koch
Center for Decision Neuroscience, Copenhagen Business School
Abstract: Theory of Mind – how to see the possibilities and limitations in a private household
budget from the perspective of your partner. Disagreement about the economy in a relationship is
a well known factor, when couples decide to divorce. The question is, how can we gain more
knowledge about the kind of decision-making involved in managing private household budgets,
and how couples negotiate about how to spend their money together? In this proposed EEG/ ERP
study we will set up a Visual Perspective Taking task, in order to examine the possible difference in
complexity and time spend to make a decision, when asked to make judgements about household
budget strategies and future spendings. The experiment will be set up, so that the participant will
solve the task in two conditions – either from his/hers own visual perspective or from the visual
perspective of an avatar. Each condition will consists of three categories, where we will take the
following themes into considerations; 1/ Cultural norms, our upbringing, and society may provides
us with certain values, which influence on the decision we make in daily life. 2/ If we have
economic secrets, which we don’t tell our partner about, it may create inconsistencies and lead to
breach of trust. 3/ The ability to read the partners mind and needs, seems helpful when planning
future strategies more successfully together.
Natan Napiorkowski
General and Experimental Psychology, LMU Munich
Abstract: Investigating ERP correlates for attentional processes. Described project is
currently being realized at Ludwig Maximilians University in Munich, Germany. It is a part of
Individualised Diagnostics & Rehabilitation of Attention Disorders training network which aims to
investigate and improve diagnostics and rehabilitation of attentional disorders. Theoretical basis of
the current project is Theory Of Visual Attention (Bundesen,1990). TVA describes functioning of
visual attention and visual short-term memory by number of parameters such as attentional
weighting, processing speed or short-term memory capacity. The aim of the project is to
investigate relationship between aforementioned parameters, EEG signal features and aging in
order to improve diagnostics of Mild Cognitive Disorders. In our research we are going to assess 3
groups of participant: Aged >30, healthy, aged >60 healthy and aged >60 suffering from Mild
Cognitive Disorder. Assessment is being done using two behavioral paradigms that measure
parameters postulated by the Theory. During the experiment we record 64 channels EEG data to
calculate lateralized, occipital ERP components related to attentional and memory processes.
Moreover, before each session resting state EEG is recorded to investigate differences between
healthy and MCI participants. Obtained results will be correlated with neuroimaging data.
Nina Hiebel & Hubert D. Zimmer
General Psychology, Saarland University
Abstract: Early selection mechanism: bridging the gap between attention control and
working memory capacity. The capacity of visual working memory (WM) is highly limited making
it considerably important to select only the most relevant objects. Consequentially, individual
differences in visual WM are partially due to attention-memory interactions which can happen at
multiple stages of processing. It was already shown that low-capacity individuals are poorer in
restricting irrelevant items from overloading limited WM capacity resources. We report data
providing evidence that people differing in WM capacity already differ in early gating mechanisms
enabling the selection of relevant items (N1). Participants performed a visual change detection task
in which it was necessary to remember the orientation of either two or five rectangles in either the
left or right hemifield, as indicated by a cue, while we recorded event-related potentials. After a
brief delay memory was tested by presenting only one object that was either identical or differed by
orientation. On a third of the trials (=filtering), participants were required to select only the relevant
rectangles indicated by a certain color presented among distractors. We compared the N1 elicited
in the filtering condition with trials that only contained relevant objects. Specifically, we expected
lower amplitude in the filtering condition than set size five if early selection processes already boost
the gating of task relevant stimuli. This N1 effect of the selection process was found for high- but
not low-WM capacity individuals. Additionally, the decrement in amplitude in the filtering condition
to set size five was larger for high- than low-WM capacity individuals.
Adrien Martel
TCD Institute of Neuroscience, Trinity College Dublin
Abstract: EEG-based Neurofeedback for sustained attention enhancement. Recent EEG
studies have identified neurophysiological signals reflecting inadequate task engagement
preceding attentional lapses. O'Connell et al. (2009) observed a modulation of the α-activity 20 s
and of the contingent negative variation (CNV) and P3 four to five s before a lapse of attention in a
temporal expectancy task. Martel et al. (2014) found a decrease in P3 amplitude and increase in αactivity foreshadowing a miss by up to 10 s in a covert sustained attention task. Concurrently,
Neurofeedback approaches have been successfully applied to attentional disorders such as ADHD
(Arns et al., 2009; Moriyama et al., 2012; Duric et al., 2012) and have been shown to enhance
visual attention, peripheral attention (Nan et al., 2013) and sustained attention (Lee et al. 2013).
Based on theses findings, the goal of the current research is to implement an EEG-based
Neurofeedback using Brain-computer interface methods (Source Power Comodulation – Dähne et
al. 2014 & Common spatial patterns – Blankertz et al. 2008), which will provide participants with
real-time information of their task engagement and warn them if a propensity towards attentional
drifting is detected in a modified Mackworth Clock. Furthermore, whether Neurofeedback is a
viable approach for improving and/or enhancing sustained attention will also be explored. The
potential improvements of Neurofeedback application on the regulation of task engagement by the
locus coeruleus-noradrenergic system will also be investigated by means of pupillometry (Murphy
et al. 2011).
Bart Cooreman, Iris Wiegand, Anders Petersen, Signe Vangkilde, & Claus Bundesen
Center for Visual Cognition
Abstract: Cue-it? We say: block-it! Paradigms developed to study lateralized ERP-components,
for instance, N2pc or Contralateral Delay Activity (CDA) – components associated with visual
attention and working memory, respectively – often make use of a spatial pre-cue (e.g. the bilateral
change detection paradigm, Vogel and Machizawa, 2004). Those components present themselves
as minor deviations in contra-minus-ipsilateral difference waveforms, and therefore, require a
lateralized stimulus presentation: attended and unattended stimuli shown in the right or left hemifield, respectively. The spatial pre-cue, often an arrow, is then used to guide participants’ covert
attention to one or the other hemi-field. Although we do not argue that cueing is necessarily
problematic or “wrong” in this context, it does disturb pre-stimulus activity, and, for this and other
reasons, can be considered undesirable in some contexts.
We hypothesized that a simple alternative might, in fact, be equally effective for isolating CDA: a
blocked design. Our EEG-study directly compares a blocked and pre-cued version of a five-letter
whole report, in which participants identify “red” letters in one hemi-field and ignore “blue”
scrambled letters in the other hemi-field; in the pre-cued version trials were intermixed regarding
the attended hemi-field, whereas in the blocked version stimuli were shown in one or the other
hemi-field in all trials of a given block. Previously, using an almost identical pre-cued paradigm,
Wiegand et al. (2004) reported a correlation between individual ’s CDA amplitude and visual short
term memory capacity as modeled by Bundesen’s Theory of Visual Attention (TVA) (Bundesen,
1990) – an important addition to previous findings regarding individual ’s CDA amplitude and
working memory capacity (Vogel and Machizawa, 2004). Our preliminary data (N=7) suggests that
a blocked design, indeed, is equally effective in both estimation of TVA-parameters and isolation of
CDA. In favor of the blocked design, however, participants seem to make less horizontal eye-
movements, and most important, pre-stimulus activity is significantly reduced, resulting in a more
reliable baseline signal. A blocked design might therefore be considered a valid alternative for
cuing. We say: block-it!
Lisbeth Højkjær Larsen
Department of Neuroscience and Pharmacology, University of Copenhagen
Abstract: Central nervous adaptations following 30 min of fine-motor practice on a
computer tablet. Background: The interaction between brain regions that enable us to learn and
remember skilled movements has been addressed with increasing intensity in neuroscience over
the past two decades. Despite this, data elucidating the dynamics in the motor network that enable
movements at different levels of behavioural performance still remain scarce. The objective of this
study is to investigate the effect of fine-motor practice on regional cortical interactions and on the
cortico-spinal drive. Method: Electroencephalography and electromyography will be measured from
the brain and involved muscles simultaneously during repeated trials of 3 sec isometric pinch grip
and 4 seconds rest before and after 30 min of fine-motor practice on a computer tablet in 15
healthy young females. Changes in inter-regional coupling within the contralateral hemisphere
between the dorsolateral prefrontal cortex, the ventral premotor cortex and the primary motor
cortex will be investigated using dynamic causal modeling. Changes in the cortico-spinal drive will
be evaluated based on the coupling in the time and frequency domains (coherence) between
EEG–EMG and EMG–EMG activity. Perspectives: Understanding neural correlations and how
these interact during and following motor practice may provide insight into the mechanisms and
pathways responsible for motor skill learning.