This study investigates the temporal resolution capacities of the central-auditory system in a subject (NP) suffering from repetition conduction aphasia. More specifically, the patient was asked to detect brief gaps between two stretches of broadband noise (gap detection task) and to evaluate the duration of two biphasic (WN-3) continuous noise elements, starting with white noise (WN) followed by 3 kHz bandpass-filtered noise (duration discrimination task). During the gap detection task, the two portions of each stimulus were either identical (“intra-channel condition”) or differed (“inter-channel condition”) in the spectral characteristics of the leading and trailing acoustic segments. NP did not exhibit any deficits in the intra-channel condition of the gap detection task, indicating intact auditory temporal resolution across intervals of 1–3 ms. By contrast, the inter-channel condition yielded increased threshold values. Based upon the “multiple-looks” model of central-auditory processing, this profile points at a defective integration window operating across a few tens of milliseconds – a temporal range associated with critical features of the acoustic speech signal such as voice onset time and formant transitions. Additionally, NP was found impaired during a duration discrimination task addressing longer integration windows (ca. 150 ms). Concerning speech, this latter time domain approximately corresponds to the duration of stationary segmental units such as fricatives and long vowels. On the basis of our results we suggest, that the patient’s auditory timing deficits in non-speech tasks may account, at least partially, for his impairments in speech processing.
Article Outline
1. Introduction
2. Materials and methods
2.1. Case history
2.2. Intra-channel gap detection task
2.3. Inter-channel gap detection task
2.4. Duration discrimination task
3. Results
3.1. Intra-channel gap detection task
3.2. Inter-channel gap detection
3.3. Duration discrimination task
4. Discussion
Acknowledgements
References
Rammsayer, T. & Troche, S. (2010, in press) Sex differences in the processing of temporal information in the sub-second range. Personality and Individual Differences
Processing of temporal information in the sub-second range appears to be controlled by an automatic timing system. The present study examined sex-related differences in this temporal domain. For this purpose, 132 male and 144 female participants ranging in age from 18 to 39 years completed five different psychophysical timing tasks. Reliably better timing performance in males compared to females could be shown for temporal discrimination of empty intervals and rhythm perception. Males’ better performance on temporal discrimination of filled intervals and temporal-order judgment just failed to reach the 5%-level of statistical significance. No indication of a sex-related difference was found for temporal generalisation. Findings are consistent with the notion of a slightly more efficient automatic timing system in males compared to females. Furthermore, with tasks requiring temporal integration across a series of sensory events, a more holistic processing strategy applied by males may also contribute to their performance advantage.
Article Outline
1. Introduction
2. Method
2.1. Participants
2.2. Intelligence test
2.3. Psychophysical timing tasks
2.3.1. Duration discrimination
2.3.2. Temporal-discrimination tasks
2.3.3. Temporal-generalisation task
2.3.4. Temporal-order judgment (TOJ)
2.3.5. Rhythm perception
3. Results
4. Discussion
Acknowledgements
References
Westfall, J., Jasper, J. & Zelmanova (2010) Differences in time perception as a function of strength of handedness. Personality and Individual Differences, 49, 629–633
Research has established that objective measures of time rarely have a perfect correlation with subjective judgments of time. Given that proper time perception appears to depend upon access to right-hemisphere processing (e.g., Harrington, Haaland, & Knight, 1998), the present paper investigates the link between strength of handedness and subjective time judgments. In two distinctive time- associated decision-making tasks, results indicated that mixed-handers (individuals who use their non-dominant hand for at least a few activities), perceived time differently than strong-handers (individuals who use one hand predominantly). These findings signify a link between strength of handedness and different levels of interhemispheric communication, consistent with previous handedness literature, and suggest that researchers studying time perception or problems involving the perception of time should incorporate measures of handedness strength.
Article Outline
1. Introduction
1.1. Strength of handedness and interhemispheric communication
2. Method
2.1. Subjective time perception task
2.2. Delay discounting task
2.3. Edinburgh Handedness Inventory (EHI)
3. Results
3.1. Subjective time perception task
3.2. Delay discounting task
4. Discussion
Acknowledgements
References
Technorati Tags: Psychology, school psychology, educational psychology, cognitive psychology, neuropsychology, neurosciences, neurotechnology, neurology, brain, brain function, cognitive abilities, intelligence, IQ brain clock, brain timing, mental timekeeping, brain rhythms, rhythm perception, brain synchrony, brain synchronization, neural synchrony, neural synchronization, brain clock, brain injury, stroke rehabilitation, gender differences
No comments:
Post a Comment