Table 1 Summary of genetic studies investigating the impact of time perception

SLC6A3 5-HTTLPR

Group: 273 young healthy. Cognitive tasks: (memory and Face Identity Perception tasks).

Visual

Face images

Seconds range, varied for each participant.

There was neither an association between the 5HTTLPR genotype and cognitive tasks, but there might be a tendency for better performance of SL as compared with SS carriers for fEP [24].

SLC6A4 5-HTTLPR, 5HT2A T102C, DRD2/ANKK1-Taq1A, SLC6A3 3’-UTR VNTR, COMT Val158Met, MAOA VNTR, and CLOCK genes.

Group: 647 healthy individuals, Questionnaire. Cognitive test. Production and Discrimation tasks.

Visual

Auditory

1 s, 3 s, 6 s, 12 s, 15 s

Stability of an individual’s temporal accuracy and precision across in supra-second intervals (ranging from 3 s to 15 s) in the cognitive tasks and time perception tasks. Female participants are more likely to underestimate time production task when an explicit counting strategy is not employed [6].

COMT Val158Met, 5HTR2A T102C.

Group: 90 healthy Japanese. Cognitive tasks and fMRI study.

Visual

2 s, 3 s

Results demonstrate that the COMT genotypes are related to recognition accuracy, whereas the 5HTR2A genotypes are associated with RTs for recognition. In addition, strong connectivity in the cingulo-frontal networks is closely linked to a better working memory performance, regardless of the genotypes [98].

COMT Val158Met, SLC6A3 3′UTR VNTR and DRD4 exon 3 VNTR.

Group: 52 healthy Estonians. Cognitive tasks and Discrimination task.

Visual

23 ms, 70 ms, 105 ms, 735 ms,

SLC6A3 variability no showed difference in study. COMT Val158Met and DRD4 exon 3 VNTR differ in their effects on attentional functions as explicated in long-SOA metacontrast [20].

DRD2/ANKK1-Taq1A.

Group: 25 healthy individuals. Temporal or color Discrimination task and fMRI acquisition

Visual

350 ms, 400 ms, 450 ms, 550 ms, 600 ms, 650 ms; 1,4 s, 1,8 s, 2 s, 2,2 s, 2,4 s, 2,6 s.

A1 carriers of the Taq1A polymorphism exhibited worse performance on temporal task. However, greater activation in the striatum and right dorsolateral prefrontal cortex, as well as reduced volume in the cerebellar [22].

DRD2/ANKK1-Taq1A and COMT Val158Met.

Group: 41 healthy individuals. Time perception tasks. Fixed-intervals tasks.

Visual

10s, 17 s.

DRD2/ANKK1-Taq1A in the striatum and COMT Val158Met, affecting the breakdown of dopamine in the prefrontal cortex— to interval timing and reward magnitude modulation of decision thresholds [7].

COMT Val158Met, SLC6A3 3’-UTR VNTR.

Group: 95 healthy individuals. 64-channel EEG study. Continuous performance test.

Visual

450 ms, 600 ms, 750 ms, 900 ms.

Effects of SLC6A3 and COMT on the occipito-temporal activity in CNV. In addition, there was a trend towards an interaction between the two polymorphisms [19].

SLC6A3 +/+ rats

SLC6A3 −/− rats

SLC6A3 +/− rats

Group: DAT-mutant rat. Peak interval task. Administration: Methamphetamine hydrochloride.

Visual

15 s, 20s, 45 s, 140 s, 200 s.

Complete loss of temporal control and altered sensitivity to drugs. Lower threshold for initiating responding in the timing task [8].

DRD2/ANKK1-Taq1A and COMT Val158Met.

Group: 65 healthy individuals. Temporal discrimination task and motor tempo task.

Visual

500 ms, 2 s

DRD2/ANKK1-Taq1A (A1+ allele) was associated with variability for the 500 ms duration only, whereas the COMT Val158Met (Val/Val) was associated with variability for the 2000 ms duration only. Additionally, the DRD2/ANKK1-Taq1A was associated with slower preferred motor time [21].

SLC6A3 +/+ rats

SLC6A3 −/− rats

SLC6A3 +/− rats

Group: KD rat and WT rat. Peak interval task and administration of the Raclopride.

Visual

20s, 40s, 60s, 80s, 100 s, 120 s.

DAT KD rats responded at higher levels in peak trials than WT rats in all conditions, but particularly during the fixed-interval 30 peak trials [1].

SLC6A4 5-HTTLPR, 5HT2A T102C, DRD2/ANKK1-Taq1A, SLC6A3 3’-UTR VNTR and COMT Val158Met.

Group: 44 healthy individuals. Discrimination task.

Visual

Auditory

Combinations of supra seconds.

No differences between time representation and dopamine-genes. However, show association between serotinine-related genes and parameters derived from psychometric functions PSE [13].

DRD2/ANKK1-Taq1A

Group: Transgenic rat C57BL/6-CB. Peak interval tasks.

No

Fixed-interval: 24 s.

Overexpression of D2 receptors in the striatum caused a reduction in operant response rate, a broadening of the distribution of operant responses in time and an increase in the latency of the peak in response rate, consistent with an impairment in timing accuracy. The progressive ratio operant task confirmed that D2 overexpressing rats exhibited reduced operant motivation [23].