The effect of mild depression on time discrimination

Behavioural Processes, 2009

This study examined changes in time perception as a function of depressive symptoms, assessed for each participant with the Beck Depression Inventory (BDI). The participants performed a temporal bisection task in which they had to categorize a signal duration of between 400 and 1600 ms as either as short or long. The data showed that the bisection function was shifted toward the right, and that the point of subjective equality was higher in the depressive than in the non-depressive participants. Furthermore, the higher the depression score was, the shorter the signal duration was judged to be. In contrast, the sensitivity to time was similar in these two groups of participants. These results thus indicate that the probe durations were underestimated by the depressive participants. The sadness scores assessed by the Brief Mood Inventory Scale (BMIS) also suggest that the emotional state of sadness in the depressive participants goes some way to explaining their temporal performance. Statistical analyses and modeling of data support the idea according to which these results may be explained by a slowing down of the internal clock in the depressive participants.

There is consistent evidence that depressive state affects time perception, although the relevant mechanisms are unclear. We used three paradigms to investigate such effects. The first uses production and verbal estimation of time in seconds, controversial in other studies. There were no significant depression effects for psychophysical functions. The second uses operant learning, an innovation for humans. Depressed participants gave longer estimates than non depressed participants for intervals preceding a change in external contingencies. The third uses a modified staircase to find 75% discrimination thresholds for shorter (50ms) and longer (1000ms) intervals. Depressed people have worse discrimination for longer intervals only. These results suggest that neither long term memory for times in seconds nor internal clock speed are implicated in mood effects in time perception. Mood differences are more likely to be due to attention paid to external stimuli and contexts

Frontiers in Psychology, 2014

Depressed patients frequently report a subjective slowing of the passage of time. However, experimental demonstrations of altered time perception in depressed patients are not conclusive. We added a timed action task (time-to-contact estimation, TTC) and compared this indirect time perception task to the more direct classical methods of verbal time estimation, time production, and time reproduction. In the TTC estimation task, the deviations of the estimates from the veridical values (relative errors) revealed no differences between depressed patients (N = 22) and healthy controls (N = 22). Neither did the relative errors of the TTC estimates differ between groups. There was a weak trend toward higher variability of the estimates in depressed patients but only at the shortest TTC and at the fastest velocities. Time experience (subjective flow of time) as well as time perception in terms of interval timing (verbal estimation, time production, time reproduction) performed on the same subjects likewise failed to produce effects of depression. We conclude that the notion that depression has a sizeable effect on time perception cannot be maintained.

Acta Psychiatrica Scandinavica, 2004

The effect of mild depression on time estimation and production was investigated. Participants made both magnitude estimation and magnitude production judgments for five time intervals (specified in seconds) from 3 sec to 65 sec. The parameters of the best fitting psychophysical function (power law exponent, intercept, and threshold) were determined individually for each participant in every condition. There were no significant effects of mood (high BDI, low BDI) or judgment (estimation, production) on the mean exponent, n = .98, 95% confidence interval (.96-1.04) or on the threshold. However, the intercept showed a 'depressive realism' effect, where high BDI participants had a smaller deviation from accuracy and a smaller difference between estimation and judgment than low BDI participants. Accuracy bias was assessed using three measures of accuracy: difference, defined as psychological time minus physical time, ratio, defined as psychological time divided by physical time, and a new logarithmic accuracy measure defined as ln (ratio). The ln (ratio) measure was shown to have approximately normal residuals when subjected to a mixed ANOVA with mood as a between groups explanatory factor and judgment and time category as repeated measures explanatory factors. The residuals of the other two accuracy measures flagrantly violated normality. The mixed ANOVAs of accuracy also showed a strong depressive realism effect, just like the intercepts of the psychophysical functions. There was also a strong negative correlation between estimation and production judgments. Taken together these findings support a clock model of time estimation, combined with additional cognitive mechanisms to account for the depressive realism effect. The findings also suggest strong methodological recommendations.

Emotion Review, 2012

I examine several aspects of the experience of time in depression and in the experience of different emotions. Both phenomenological and experimental studies show that depressed subjects have a slowed experience of time flow and tend to overestimate time spans. In comparison to patients in control conditions, depressed patients tend to be preoccupied with past events, and less focused on

Abnormality of subjective time experienceis well recognisedin psychiatric illness. Earlierauthors suggested that slowedtimeexperience indepression isan aspect ofpsychomotor retardation, while more recently it hasbeenarguedthatthis disturbance isnon-specifically linked tothe globalseverityof the depressivesyndrome.This study offers evidencethat both views can be justified:slowedtime awarenessis a commonsymptomof depression, relatedparticularly toretardation, andtotheseverity ofthemood disturbance. Some oftheexperimental difficulties inthis kindofresearch areillustrated.

European Psychiatry, 2008

Patients with affective disorders have often been reported to experience subjective changes in how they perceive the flow of time. Time reproduction tasks provide information about the memory component of time perception and are thought to remain unaffected by pulse rate disturbances in the pacemaker of the internal clock.

The Quarterly Journal of Experimental Psychology, 2008

An experiment investigated the potential effects of lowering arousal on performance on time perception tasks. Four participant groups received different tasks: Normal and episodic temporal generalization, bisection, and verbal estimation, all involving judgements of the duration of visual stimuli. Self-rated arousal during the experimental session was lowered by spacing experimental trials approximately 10 s apart. Between the early and late blocks of the experiment, performance changed on normal temporal generalization and verbal estimation, but not on episodic temporal generalization and bisection. The changes were consistent with the idea that the pacemaker of the participant's internal clock had been slowed down by the slow trial spacing. Results suggested that bisection was based on a criterion that adjusted during the experiment, whereas verbal estimation was based on preexisting standards, or those established early in the experiment.

Brain Informatics

Background: Models of time perception share an element of scalar expectancy theory known as the internal clock, containing specific mechanisms by which the brain is able to experience time passing and function effectively. A debate exists about whether to treat factors that influence these internal clock mechanisms (e.g., emotion, personality, executive functions, and related neurophysiological components) as arousal-or attentional-based factors. Purpose: This study investigated behavioral and neurophysiological responses to an affective time perception Go/ NoGo task, taking into account the behavioral inhibition (BIS) and behavioral activation systems (BASs), which are components of reinforcement sensitivity theory. Methods: After completion of self-report inventories assessing personality traits, electroencephalogram (EEG/ERP) and behavioral recordings of 32 women and 13 men recruited from introductory psychology classes were completed during an affective time perception Go/NoGo task. This task required participants to respond (Go) and inhibit (NoGo) to positive and negative affective visual stimuli of various durations in comparison to a standard duration. Results: Higher BAS scores (especially BAS Drive) were associated with overestimation bias scores for positive stimuli, while BIS scores were not correlated with overestimation bias scores. Furthermore, higher BIS Total scores were associated with higher N2d amplitudes during positive stimulus presentation for 280 ms, while higher BAS Total scores were associated with higher N2d amplitudes during negative stimuli presentation for 910 ms. Discussion: Findings are discussed in terms of arousal-based models of time perception, and suggestions for future research are considered.