title: Revisiting the Temporal Resolution Power (TRP) Hypothesis: An Investigation of the Behavioral and Psychophysiological Aspects of the Relationship Between TRP and Psychometric Intelligence
Creators: name: Makowski, Lisa Michaela
Publisher: name: Universität Bern
Year: 2024
Subjects: subject: 150 Psychology
subject: 370 Education

description: The Temporal Resolution Power (TRP) hypothesis states that individuals who exhibit greater accuracy and sensitivity in temporal information processing tasks also process information faster, coordinate their information processing more effectively, and, therefore, perform better on psychometric intelligence tasks. As an explanation for these individual differences in TRP, it has been suggested that individuals differ in an internal master clock that ticks at a specific rate, which should be reflected in the form of neural oscillations. However, how these neural oscillations can be represented on a psychophysiological level is still unknown. Moreover, as the first part of the TRP hypothesis is merely well established, less is known about its association with the coordination of mental operations. From this perspective, the overall aim of this dissertation was to strengthen and extend the TRP hypothesis at the behavioral and psychophysiological levels. To this end, four studies were conducted in which different aspects of the TRP hypothesis were investigated. 
In Study 1 (N = 273, M = 21.6, SD = 2.7), the association between TRP, spatial suppression, as another information processing mechanism, and psychometric intelligence was analyzed on a behavioral level. Study 2 (N = 129, M = 23.0, SD = 3.1) examined to what extent an internal master clock can be reflected on the psychophysiological level by the peak alpha frequency (PAF) measured during resting states, and whether the PAF can mediate the relationship between TRP and psychometric intelligence. Study 3 (N = 228, M = 22.0, SD = 2.9) focused on the second part of the TRP hypothesis by investigating to what extent working memory updating, as a reflection of the coordination of mental operations, mediates the relationship between TRP and psychometric intelligence. In Study 4, a subsample of Study 2 was selected with N = 100 (M = 22.8, SD = 2.9) to investigate how, besides an internal clock mechanism, the involvement of other processing during TRP tasks may be important for understanding the relationship between temporal information processing and psychometric intelligence. 
The results showed that the relationship between psychometric intelligence and TRP could be successfully replicated in Studies 1-3. Moreover, in line with the first part of the TRP hypothesis, individuals with higher TRP were also faster in correctly identifying the motion direction of presented visual stimuli (Study 1). Spatial suppression, however, could not make a functional contribution. In line with the second part of the TRP hypothesis, higher TRP also enabled a more effective coordination of mental operations, as indicated by a higher working memory updating, which in turn then also led to higher psychometric intelligence performance (Study 3). Regarding the psychophysiological basis of TRP, although the frontal/central PAF when measured during resting states with eyes open was positively related to psychometric intelligence, it was not associated with TRP (Study 2). The investigation of neural activity during temporal information processing based on theta and gamma coherence also showed no significant correlation with temporal information processing performance when psychometric differences in intelligence were considered (Study 4). Thus, the individual differences in TRP could neither be explained by the PAF measured at rest nor its relationship to psychometric intelligence by the coherence measures measured during the task. 
Based on these four studies, the TRP hypothesis could be further replicated and extended. More specifically, Studies 1 to 3 provided further evidence for TRP as a substantial predictor of psychometric intelligence. Furthermore, the aspects of processing speed and coordination within the TRP hypothesis were confirmed in two new studies. However, it was also shown that spatial suppression was unable to contribute. Besides these behavioral aspects, it was also focused, as the first study to date, on how the internal master clock might be reflected on the psychophysiological level. Even if no clear measure could be found, the analyses offer initial starting points for future studies. This dissertation can, therefore, make an important contribution to the explanation and understanding of the TRP hypothesis and brings us one step closer to understanding why individuals differ in their general intelligence.