Visual semantics

Veel betekenisaspecten van taal liggen opgeslagen in het semantische geheugen. Het semantische geheugen is gebaseerd op onze ervaring met concrete objecten zoals planten, dieren en gereedschappen. Onderzoek met mensen die als gevolg van een hersenbeschadiging moeite hebben met het begrijpen van taal, heeft uitgewezen dat de betekenis van taal ook afhankelijk is van diverse sensorische en motorische gebieden van de hersenen, met name de visuele hersengebieden. Het ventrale pad is betrokken bij het herkennen van objecten, het dorsale pad maakt het mogelijk acties uit te voeren met objecten. Resultaten van experimenten die in dit proefschrift beschreven zijn geven aan dat het semantische geheugen een zeer nauwe relatie onderhoudt met het visuele systeem in onze hersenen. Dit ondersteunt ook de gedachte van een model van visuele semantiek waarin visueel-beschrijvende informatie eerst wordt opgehaald uit het lange-termijngeheugen en vervolgens wordt geactiveerd in het object-werkgeheugen. Het werkgeheugen is waarschijnlijk van belang in de koppeling tussen talige en visuele informatie. Visuele semantiek ligt dus eigenlijk op het kruispunt van semantische, visuele en talige processen Bron:Taaluniversum

Observational Learning of New Movement Sequences Is Reflected in Fronto-Parietal Coherence

Mankind is unique in her ability for observational learning, i.e. the transmission of acquired knowledge and behavioral repertoire through observation of others' actions. In the present study we used electrophysiological measures to investigate brain mechanisms of observational learning. Analysis investigated the possible functional coupling between occipital (alpha) and motor (mu) rhythms operating in the 10Hz frequency range for translating “seeing” into “doing”. Subjects observed movement sequences consisting of six consecutive left or right hand button presses directed at one of two target-buttons for subsequent imitation. Each movement sequence was presented four times, intervened by short pause intervals for sequence rehearsal. During a control task subjects observed the same movement sequences without a requirement for subsequent reproduction. Although both alpha and mu rhythms desynchronized during the imitation task relative to the control task, modulations in alpha and mu power were found to be largely independent from each other over time, arguing against a functional coupling of alpha and mu generators during observational learning. This independence was furthermore reflected in the absence of coherence between occipital and motor electrodes overlaying alpha and mu generators. Instead, coherence analysis revealed a pair of symmetric fronto-parietal networks, one over the left and one over the right hemisphere, reflecting stronger coherence during observation of movements than during pauses. Individual differences in fronto-parietal coherence were furthermore found to predict imitation accuracy. The properties of these networks, i.e. their fronto-parietal distribution, their ipsilateral organization and their sensitivity to the observation of movements, match closely with the known properties of the mirror neuron system (MNS) as studied in the macaque brain. These results indicate a functional dissociation between higher order areas for observational learning (i.e. parts of the MNS as reflected in 10Hz coherence measures) and peripheral structures (i.e. lateral occipital gyrus for alpha; central sulcus for mu) that provide low-level support for observation and motor imagery of action sequences

Evidence for fast, low level motor resonance to action observation: An MEG study

Contains fulltext : 73144.pdf (publisher's version ) (Closed access)Lateralized magnetic fields were recorded from 12 subjects using a 151 channel magnetoencephalograpy (MEG) system to investigate temporal and functional properties of motor activation to the observation of goal-directed hand movements by a virtual actor. Observation of left and right hand movements generated a neuromagnetic lateralized readiness field (LRF) over contralateral motor cortex. The early onset of the LRF and the fact that the evoked component was insensitive to the correctness of the observed action suggest the operation of a fast and automatic form of motor resonance that may precede higher levels of action understanding

Registered Replication Report: Study 3 from Trafimow and Hughes (2012)

Terror Management Theory (TMT) proposes that when people are made aware of their own death, they are more likely to endorse cultural values. TMT is a staple of social psychology, being featured prominently in textbooks and the subject of much research. The implications associated with TMT are significant, as its advocates claim it can partially explain cultural conflicts, intergroup antagonisms, and even war. However, considerable ambiguity regarding effect size exists, and no preregistered replication of death-thought accessibility findings exists. Moreover, there is debate regarding the role of time delay between the manipulation of mortality salience and assessment of key measures. We present results from 22 labs in 11 countries (total N = 3,447) attempting to replicate and extend an existing study of terror management theory, study three from Trafimow and Hughes (2012), and the role of time delay effects. While we failed to replicate the specific findings from Trafimow and Hughes (2012), we did demonstrate that it is possible to prime death-related thoughts, and that priming is more effective when there is no delay between the priming and outcome measure. Implications for future research and terror management theory are discussed