scholarly journals Temporal Dynamics of Attention during Encoding versus Maintenance of Working Memory: Complementary Views from Event-related Potentials and Alpha-band Oscillations

2015 ◽  
Vol 27 (3) ◽  
pp. 492-508 ◽  
Author(s):  
Nicholas E. Myers ◽  
Lena Walther ◽  
George Wallis ◽  
Mark G. Stokes ◽  
Anna C. Nobre

Working memory (WM) is strongly influenced by attention. In visual WM tasks, recall performance can be improved by an attention-guiding cue presented before encoding (precue) or during maintenance (retrocue). Although precues and retrocues recruit a similar frontoparietal control network, the two are likely to exhibit some processing differences, because precues invite anticipation of upcoming information whereas retrocues may guide prioritization, protection, and selection of information already in mind. Here we explored the behavioral and electrophysiological differences between precueing and retrocueing in a new visual WM task designed to permit a direct comparison between cueing conditions. We found marked differences in ERP profiles between the precue and retrocue conditions. In line with precues primarily generating an anticipatory shift of attention toward the location of an upcoming item, we found a robust lateralization in late cue-evoked potentials associated with target anticipation. Retrocues elicited a different pattern of ERPs that was compatible with an early selection mechanism, but not with stimulus anticipation. In contrast to the distinct ERP patterns, alpha-band (8–14 Hz) lateralization was indistinguishable between cue types (reflecting, in both conditions, the location of the cued item). We speculate that, whereas alpha-band lateralization after a precue is likely to enable anticipatory attention, lateralization after a retrocue may instead enable the controlled spatiotopic access to recently encoded visual information.

2014 ◽  
Vol 28 (3) ◽  
pp. 162-177 ◽  
Author(s):  
Patrick D. Gajewski ◽  
Michael Falkenstein

It is well known that working memory is one of the most vulnerable cognitive functions in elderly. However, little is known about the neuronal underpinnings and temporal dynamics of working memory mechanisms in healthy aging which are necessary to understand the age-related changes. To this end, 36 young and 36 old healthy individuals performed a 2-back task and a 0-back control task, while the electroencephalogram (EEG) was recorded. Participants were instructed to press a response key whenever a target appeared and not to respond in case of nontargets. Expectedly, older participants showed considerably slower RTs and significantly higher rates of omitted targets and false alarms than young participants in the 2-back task, whereas no age-group difference in detection rate was found in the 0-back task. From the EEG event-related potentials as well as time-frequency plots were computed. The ERPs showed a general delay of the frontocentral N2, and an attenuation and delay of both the P3a and P3b in older versus younger adults. Importantly, the frontal P3a was reduced in older adults in the 2-back task. Time-frequency decomposition revealed consistently lower power in frontal theta (6 Hz) and parietal alpha (9–11 Hz) frequency range in older versus younger adults whereas no age-related differences were found in the delta frequency range. Task unspecific reduction of posterior alpha in elderly was paralleled by a reduction of the P3b. In contrast, the older adults had a strongly reduced frontal theta power in the 2-back task, which parallels the P3a reduction in the ERPs. The widespread reduction of alpha may indicate that older adults needed to recruit more attentional resources for successful task performance, whereas reduced frontal theta may indicate that older adults are less able to recruit frontal resources related to top-down control with increasing task demands. This suggests a less efficient fronto-parietal network synchronicity in older individuals that leads to deficits in identification and maintenance of task relevant stimuli.


2010 ◽  
Vol 104 (2) ◽  
pp. 972-983 ◽  
Author(s):  
M. van Elk ◽  
H. T. van Schie ◽  
S.F.W. Neggers ◽  
H. Bekkering

The present study investigated the selection for action hypothesis, according to which a subject's action intention to perform a movement influences the way in which visual information is being processed. Subjects were instructed in separate blocks either to grasp or to point to a three-dimensional target-object and event-related potentials were recorded relative to stimulus onset. It was found that grasping compared with pointing resulted in a stronger N1 component and a subsequent selection negativity, which were localized to the lateral occipital complex. These effects suggest that the intention to grasp influences the processing of action-relevant features in ventral stream areas already at an early stage (e.g., enhanced processing of object orientation for grasping). These findings provide new insight in the neural and temporal dynamics underlying perception–action coupling and provide neural evidence for a selection for action principle in early human visual processing.


2017 ◽  
Vol 15 (4) ◽  
pp. 365-389
Author(s):  
Maria Pąchalska ◽  
Jolanta Góral-Pólrola ◽  
Andreas Mueller ◽  
Juri D. Kropotov

Perception is one of the psychological operations that can be analyzed from the point of view of microgenetic theory. Our study tests the basic premise of microgenesis theory – the existence of recurrent stages of visual information processing. The event related potentials in two variants of a cued GO/NOGO task (contrasting images of Animals and Plants in the first variant, and contrasting images of Angry and Happy faces in the second variant) were studied during the first 300 ms following stimulus presentation. The independent component analysis was applied to a large collection of ERPs. The functional independent components associated with visual category discrimination, comparison to working memory, action initiation and conflict detection were separated. Information processing in the ventral visual stream (the temporal independent components) occurs at two sequential stages with positive/negative fluctuations of the cortical potential as indexes of the stages. The first stage represents the comparison of the pure physical features of the visual input with the memory trace. The second stage represents the comparison of more sophisticated semantic/emotional features with the working memory. The two stages are the results of interplay between bottom-up and top-down projections in the visual ventral stream.


2009 ◽  
Vol 23 (2) ◽  
pp. 63-76 ◽  
Author(s):  
Silke Paulmann ◽  
Sarah Jessen ◽  
Sonja A. Kotz

The multimodal nature of human communication has been well established. Yet few empirical studies have systematically examined the widely held belief that this form of perception is facilitated in comparison to unimodal or bimodal perception. In the current experiment we first explored the processing of unimodally presented facial expressions. Furthermore, auditory (prosodic and/or lexical-semantic) information was presented together with the visual information to investigate the processing of bimodal (facial and prosodic cues) and multimodal (facial, lexic, and prosodic cues) human communication. Participants engaged in an identity identification task, while event-related potentials (ERPs) were being recorded to examine early processing mechanisms as reflected in the P200 and N300 component. While the former component has repeatedly been linked to physical property stimulus processing, the latter has been linked to more evaluative “meaning-related” processing. A direct relationship between P200 and N300 amplitude and the number of information channels present was found. The multimodal-channel condition elicited the smallest amplitude in the P200 and N300 components, followed by an increased amplitude in each component for the bimodal-channel condition. The largest amplitude was observed for the unimodal condition. These data suggest that multimodal information induces clear facilitation in comparison to unimodal or bimodal information. The advantage of multimodal perception as reflected in the P200 and N300 components may thus reflect one of the mechanisms allowing for fast and accurate information processing in human communication.


2002 ◽  
Vol 16 (2) ◽  
pp. 114-118 ◽  
Author(s):  
Timo Ruusuvirta ◽  
Heikki Hämäläinen

Abstract Human event-related potentials (ERPs) to a tone continuously alternating between its two spatial loci of origin (middle-standards, left-standards), to repetitions of left-standards (oddball-deviants), and to the tones originally representing these repetitions presented alone (alone-deviants) were recorded in free-field conditions. During the recordings (Fz, Cz, Pz, M1, and M2 referenced to nose), the subjects watched a silent movie. Oddball-deviants elicited a spatially diffuse two-peaked deflection of positive polarity. It differed from a deflection elicited by left-standards and commenced earlier than a prominent deflection of negative polarity (N1) elicited by alone-deviants. The results are discussed in the context of the mismatch negativity (MMN) and previous findings of dissociation between spatial and non-spatial information in auditory working memory.


2014 ◽  
Vol 29 (8) ◽  
pp. 463-472 ◽  
Author(s):  
S. Corbera ◽  
S. Ikezawa ◽  
M.D. Bell ◽  
B.E. Wexler

AbstractEmpathy is crucial for maintaining effective social interactions. Research has identified both an early-emotional sharing and a late-cognitive component of empathy. Although considered a functionally vital social cognition process, empathy has scarcely been studied in schizophrenia (SZ). We used event-related potentials (ERPs) to study the temporal dynamics of empathic response in 19 patients with SZ and 18 matched healthy controls (HC) using an empathy for physical pain paradigm. Participants responded to pictures of hands in neutral and painful situations in an active empathic condition and one manipulated by task demands. Additionally, subjective ratings of the stimuli and empathic self-reports were collected. People with SZ had (1) decreased early-emotional ERP responses to pictures of others in pain; (2) decreased modulation by attention of late-cognitive ERP responses; (3) lower ratings of perspective taking and higher ratings of personal distress which were both related to decreased modulation of late-cognitive empathic responses; (4) a significant relationship between high affective overlap between somebody else's pain and their own pain and decreased modulation of late-cognitive empathic responses; (5) a distinct relationship between regulatory deficits in late-cognitive empathy and functioning. Patients had present but reduced early and late empathy-related ERPs. Patients also reported increased personal distress when faced with distress in others. The late ERP responses are thought to be associated with self-regulation and response modulation. The magnitude of these late responses was inversely associated with reported levels of personal distress in both patients and controls. Additionally, regulatory deficits in cognitive empathy were highly related with deficits in functioning. Decreased ability to regulate one's own emotional engagement and response to emotions of others may be an important source of distress and dysfunction in social situations for patients with schizophrenia.


2006 ◽  
Vol 21 (2) ◽  
pp. 135-137 ◽  
Author(s):  
Ioannis A. Liappas ◽  
Charalabos C. Papageorgiou ◽  
Andreas D. Rabavilas

AbstractZolpidem is a GABA (A) agonist, which is indicated for the short-term management of insomnia. Recent research provide evidence suggesting that zolpidem produces spatial working memory (WM) deficits and dependence; however, the underlying mechanisms of these effects are unknown. Since the auditory N400 component of event-related potentials (ERPS) is considered as an index of memory use of context processing, the present study focused on N400 waveform of ERPs elicited during a WM task in a case suffering from zolpidem dependence. The patterns of N400 waveform of this case were compared to the patterns obtained from healthy controls. This comparison revealed that zolpidem dependence is accompanied by reduced amplitudes located at posterior brain areas and diffuse prolongation of N400. These findings may indicate that zolpidem dependence manifests alterations with regard to the memory use of context processing, involving or affecting a wide-ranging network of the brain's structures.


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