Search results for " discrimination"

Primary motor area contribution to attentional reorienting after distraction

2008

The anatomical structures involved in distraction-related processing in the auditory domain were investigated using magnetoencephalography. Participants performed a duration-discrimination task on a sequence of 200 and 400 ms long tones. Infrequent (12%) task-irrelevant pitch changes resulted in slower discriminative responses and more errors. Event-related potentials to these changes show an increased N1, a mismatch negativity, a P3a, and a reorienting negativity. The event-related magnetic fields revealed focal activities in superior and medial temporal areas in the N1/mismatch negativity time range. No significant activity was found in the P3a interval. In the reorienting negativity inte…

Functional relevance of cross-modal plasticity in blind humans

1997

Functional imaging studies of people who were blind from an early age have revealed that their primary visual cortex can be activated by Braille reading and other tactile discrimination tasks1. Other studies have also shown that visual cortical areas can be activated by somatosensory input in blind subjects but not those with sight2,3,4,5,6,7. The significance of this cross-modal plasticity is unclear, however, as it is not known whether the visual cortex can process somatosensory information in a functionally relevant way. To address this issue, we used transcranial magnetic stimulation to disrupt the function of different cortical areas in people who were blind from an early age as they i…

Anxiety, Stress, and Contingent Negative Variation Reconsidered

1984

Neural discrimination of nonprototypical chords in music experts and laymen:an MEG study

2009

Abstract At the level of the auditory cortex, musicians discriminate pitch changes more accurately than nonmusicians. However, it is not agreed upon how sound familiarity and musical expertise interact in the formation of pitch-change discrimination skills, that is, whether musicians possess musical pitch discrimination abilities that are generally more accurate than in nonmusicians or, alternatively, whether they may be distinguished from nonmusicians particularly with respect to the discrimination of nonprototypical sounds that do not play a reference role in Western tonal music. To resolve this, we used magnetoencephalography (MEG) to measure the change-related magnetic mismatch response…

Latencies of the P300 component of the auditory event-related potential in depression are related to the Bech-Rafaelsen Melancholia Scale but not to …

1991

The relationship between severity of depression and the P300 latency of auditory event-related potential was investigated in 36 patients with a major depressive episode according to DSM-III. Positive correlations were found between of the P300 latency and the total score of the Bech-Rafaelsen Melancholia Scale (BRMS), the 4 retardation items of the BRMS (motor, verbal, intellectual and emotional) and the item for lowered mood. In contrast, latencies were not associated with the scores of the Hamilton Rating Scale for Depression, which considers retardation to a lesser extent than the BRMS.

The time course of temporal discrimination: An ERP study

2009

Objective: The question of how temporal information is processed by the brain is still a matter of debate. This study aimed to elucidate the brain electrical activity associated with a visual temporal discrimination task. Methods: For this purpose, 44 participants were required to compare pairs of sequentially presented time intervals: a fixed standard interval (1000 ms), and an equal-to-standard, longer (1200 ms) or shorter (800 ms) comparison interval. Behavioural data and event-related potentials (ERPs) were analyzed. Results: Long intervals were more rapidly identified than short intervals. The amplitude of the contingent negative variation (CNV) found at frontocentral sites before the …

An automatic test for frequency discrimination

1987

Békésy audiometry has been applied to the determination of the frequency discrimination threshold. The automatic test for frequency discrimination is performed by means of a modified automatic audiometer at fixed frequencies, each administered for a duration of 60 s. The test involves the stimulus of a series of pairs of tone bursts of 500 ms duration: the frequency of one of the tone bursts (f0) is constant, while the other (f0 + delta f) gradually increases and decreases according to the subject's response. The tracings obtained facilitate the evaluation of the discrimination capability of the subject. The pattern obtained from a sample of normally hearing people was analysed in order to …

Sievietes militārajā dienestā: Dienējošu sieviešu pieredze vīriešu dominējošā vidē

2021

Militārā joma vēsturiski un sociāli tiek definēta kā tradicionāli vīrišķīga – tā ir, iespējams, viena no arhetipiski vīrišķīgākajām sociālajām struktūrām Rietumu sabiedrībā (Segal 1995). Taču militārajā dienestā un karadarbībā tik un tā sastopamas arī sievietes. Šajā bakalaura darbā pētīta 23 sieviešu pieredze, kuras visas dienē vai dienējušas Kanādas Bruņotajos spēkos (KBS) pēdējo četrdesmit gadu laikā. Šo sieviešu pieredze apkopota daļēji strukturētās intervijās, kas veiktas gan klātienē, gan rakstiskā formātā. Izmantojot Pjēra Burdjē teoriju par maskulīno dominanci un Reivinas Konelas koncepciju par maskulīno hegemoniju, darbā esmu pētījusi, kā sievietes pieredz militāro vidi caur dzimtē…

Auditory cortical event-related potentials to pitch deviances in rats

1998

Abstract We recorded epidural event-related potentials (ERPs) from the auditory cortex in anesthetized rats when pitch-deviant tones were presented in a homogenous series of standard tones (oddball condition). Additionally, deviant tones were presented without standard tones (deviant-alone condition). ERPs to deviant tones in the oddball condition differed significantly from ERPs to standard tones at the latency range of 63–243 ms. On the other hand, ERPs to deviant tones in the deviant-alone condition did not differ from ERPs to standard tones until 196 ms from stimulus onset. The results suggest that oddball stimuli can be neurophysiologically discriminated in anesthetized rats. Furthermo…

The impact of a concurrent motor task on auditory and visual temporal discrimination tasks

2016

Previous studies have shown the presence of an interference effect on temporal perception when participants are required to simultaneously execute a nontemporal task. Such interference likely has an attentional source. In the present work, a temporal discrimination task was performed alone or together with a self-paced finger-tapping task used as concurrent, nontemporal task. Temporal durations were presented in either the visual or the auditory modality, and two standard durations (500 and 1, 500 ms) were used. For each experimental condition, the participant’s threshold was estimated and analyzed. The mean Weber fraction was higher in the visual than in the auditory modality, but only for…