Visual Mismatch Negativity and Categorization

Visual mismatch negativity (vMMN) component of event-related potentials is elicited by stimuli violating the category rule of stimulus sequences, even if such stimuli are outside the focus of attention. Category-related vMMN emerges to colors, and color-related vMMN is sensitive to language-related effects. A higher-order perceptual category, bilateral symmetry is also represented in the memory processes underlying vMMN. As a relatively large body of research shows, violating the emotional category of human faces elicits vMMN. Another face-related category sensitive to the violation of regular presentation is gender. Finally, vMMN was elicited to the laterality of hands. As results on category-related vMMN show, stimulus representation in the non-conscious change detection system is fairly complex, and it is not restricted to the registration of elementary perceptual regularities

Inger-vezérelt és figyelmi integrációs folyamatok az észlelésben = Stimulus-driven and attentive integration processes in perception

A beérkező szenzoros információk nagyobb egységekbe szervezése (integrációja) az észlelő és kognitív rendszer egyik legfőbb feladata. A pályázat során négy területen vizsgáltunk integrációs-szegregációs folyamatokat. 1) Megállapítottuk, hogy az akusztikus vonások egységes inger-reprezentációba integrálása figyelem nélkül is megtörténik, bár figyelmi hatások módosíthatják az integrációs folyamat eredményét. 2) Kimutattuk, hogy a hallási idői csoportosítás automatikusan készített hallási előrejelzések mentén valósul meg. 3) Elsőként találtunk olyan eseményfüggő agyi potenciál komponenst, amely integrált audiovizuális emléknyomok automatikus létrehozását mutatja az agyban. 4) Általánosítottuk a nem figyelt hangingereknek a figyelt hangok feldolgozására gyakorolt hatását vizsgáló paradigmát és átértelmeztük az egyes eseményfüggő agy potenciál komponensek által tükrözött feldolgozó részfolyamatok szerepét az elterelődés és reorientáció folyamatában. | Organizing sensory information into larger units (integration) is a primary function of the perceptual cognitive system. The funded research investigated four types of processes of integration segregation. 1) We found that acoustic features are integrated into a unitary stimulus representation even outside the focus of attention, although attentive processes may modulate the outcome of the integration process. 2) We have shown that auditory temporal grouping is guided by automatically created predictions of upcoming sounds. 3) We obtained the first event related brain potential evidence of the automatic formation of integrated audiovisual memory traces in the brain. 4) We generalized the stimulus paradigm used for studying the effects of unattended auditory stimuli on the processing of attended sounds and reinterpreted the role of the processes reflected in the various event related brain potential components in the course of distraction and reorientation

Age-related processing strategies and go–nogo effects in task-switching: an ERP study

We studied cognitive and age-related changes in three task-switching (TS) paradigms: (1) informatively cued TS with go stimuli, (2) informatively cued TS with go and nogo stimuli, (3) non-informatively cued TS with go and nogo stimuli. This design allowed a direct comparison, how informative and non-informative cues influenced preparatory processes, and how nogo stimuli changed the context of the paradigm and cognitive processing in different aging groups. Beside the behavioral measures [reaction time (RT), error rate], event-related potentials (ERPs) were registered to the cue and target stimuli in young (N = 39, mean age = 21.6 ± 1.6 years) and older (N = 40, mean age = 65.7 ± 3.2 years) adults. The results provide evidence for declining performance in the older group: they had slower RT, less hits, more erroneous responses, higher mixing costs and decreased amplitude of ERP components than the participants of the younger group. In the task without the nogo stimuli young adults kept the previous task-set active that could be seen in shorter RT and larger amplitude of cue-locked late positivity (P3b) in task repeat (TR) trials compared to task switch trials. If both go and nogo stimuli were presented, similar RTs and P3b amplitudes appeared in the TR and TS trials. In the complex task situations older adults did not evolve an appropriate task representation and task preparation, as indicated by the lack of cue-locked P3b, CNV, and target-locked P3b. We conclude that young participants developed explicit representation of task structures, but the presence of nogo stimuli had marked effects on such representation. On the other hand, older people used only implicit control strategy to solve the task, hence the basic difference between the age groups was their strategy of task execution

Extreme environment effects on cognitive functions: a longitudinal study in high altitude in Antarctica

K

Scraping sounds and disgusting noises

Thirty-four horrible sounds have been examined in an Internet-based psychoacoustic experiment. This paper presents the results for the scraping and disgusting noises used. It is not understood why some humans find certain scraping noises, such as the sound of fingernails being scraped down a blackboard, so terrible. In this experiment, the variations in ratings with age, gender and location are examined. The results for one of the scraping sounds is consistent with the hypothesis suggested by others, that the response comes from a vestigial reflex related to the warning cries of monkeys. But this was not true for the actual recording of the fingernails scraping down a blackboard. An alternative hypothesis that the response is related to an audio–haptic interaction was tested and results indicated that this idea warrants further investigation. Other possible causes of the response, drawing on work concerning dissonance, are tentatively suggested. The disgusting sounds examined included the worst sound found in the experiment, the sound of someone vomiting. However, none of the disgusting sounds tested promoted responses consistent with a ‘disgust reaction’ based purely on survival instincts. Cultural factors might be important in our response to the disgusting sounds, with the influence of manners and etiquette being suggested as a possible factor

Asymmetry of automatic change detection shown by the visual mismatch negativity: An additional feature is identified faster than missing features

In two experiments, we demonstrated that an asymmetric effect of the brain electric activity that is elicited by nonattended visual stimuli is similar to the one found in responses observed in the performance of visual search tasks. The automatic detection of violated sequential regularities was investigated by measuring the visual mismatch negativity (vMMN) component of event-related brain potentials (ERPs). In Experiment 1, within a sequence of stimulus displays with O characters, infrequently presented Q characters elicited an earlier vMMN than did infrequent O characters within a sequence of Q characters. In Experiment 2, similar asymmetric results emerged if only 16 % of the characters were different within an infrequent display. In both experiments, these stimuli were irrelevant; during the stimulus sequences, participants performed a demanding videogame. We suggest that the underlying match/mismatch and decision processes are similar in the vMMN and in the attention-related visual search paradigm, at least in the case of the stimuli in the present experiments