Perception Of Temporal Information Research Articles

Memory for Stimulus Duration Is Not Bound to Spatial Information.

Different theories have been proposed to explain how the human brain derives an accurate sense of time. One specific class of theories, intrinsic clock theories, postulate that temporal information of a stimulus is represented much like other features such as color and location, bound together to form a coherent percept. Here, we explored to what extent this holds for temporal information after it has been perceived and is held in working memory for subsequent comparison. We recorded EEG of participants who were asked to time stimuli at lateral positions of the screen followed by comparison stimuli presented in the center. Using well-established markers of working memory maintenance, we investigated whether the usage of temporal information evoked neural signatures that were indicative of the location where the stimuli had been presented, both during maintenance and during comparison. Behavior and neural measures including the contralateral delay activity, lateralized alpha suppression, and decoding analyses through time all supported the same conclusion: The representation of location was strongly involved during perception of temporal information, but when temporal information was to be used for comparison, it no longer showed a relation to spatial information. These results support a model where the initial perception of a stimulus involves intrinsic computations, but that this information is subsequently translated to a stimulus-independent format to be used to further guide behavior.

Reproduction Accuracy for Short Rhythms Following Melodic or Monotonic Presentation

Some researchers and study participants have expressed an intuition that novel rhythmic sequences are easier to recall and reproduce if they have a melody, implying that melodicity (the presence of musical pitch variation) fundamentally enhances perception and/or representation of rhythm. But the psychoacoustics literature suggests that pitch variation often impairs perception of temporal information. To examine the effect of melodicity on rhythm reproduction accuracy, we presented simple nine-note auditory rhythms to 100 college students, who attempted to reproduce those rhythms by tapping. Reproductions tended to be more accurate when the presented notes all had the same pitch than when the presented notes had a melody. Nonetheless, a plurality of participants judged that the melodically presented rhythms were easier to remember. We also found that sequences containing a Scotch snap (a sixteenth note at a quarter note beat position followed by a dotted eighth note) were reproduced less accurately than other sequences in general, and less accurately than other sequences containing a dotted eighth note.

Temporal perception is enhanced for goal-directed biological actions

ABSTRACTResearch into the visual perception of goal-directed human action indicates that human action perception makes use of specialized processing systems, similar to those that operate in visual expertise. Against this background, the current research investigated whether perception of temporal information in goal-directed human action is enhanced relative to similar motion stimuli. Experiment 1 compared observers’ sensitivity to speed changes in upright human action to a kinematic control (an animation yoked to the motion of the human hand), and also to inverted human action. Experiment 2 compared human action to a non-human motion control (a tool moved the object). In both experiments observers’ sensitivity to detecting the speed changes was higher for the human stimuli relative to the control stimuli, and inversion in Experiment 1 did not alter observers’ sensitivity. Experiment 3 compared observers’ sensitivity to speed changes in goal-directed human and dog actions, in order to determine if enhanced temporal perception is unique to human actions. Results revealed no difference between human and dog stimuli, indicating that enhanced speed perception may exist for any biological motion. Results are discussed with reference to theories of biological motion perception and perception in visual expertise.

Metabolic rate and body size are linked with perception of temporal information

Body size and metabolic rate both fundamentally constrain how species interact with their environment, and hence ultimately affect their niche. While many mechanisms leading to these constraints have been explored, their effects on the resolution at which temporal information is perceived have been largely overlooked. The visual system acts as a gateway to the dynamic environment and the relative resolution at which organisms are able to acquire and process visual information is likely to restrict their ability to interact with events around them. As both smaller size and higher metabolic rates should facilitate rapid behavioural responses, we hypothesized that these traits would favour perception of temporal change over finer timescales. Using critical flicker fusion frequency, the lowest frequency of flashing at which a flickering light source is perceived as constant, as a measure of the maximum rate of temporal information processing in the visual system, we carried out a phylogenetic comparative analysis of a wide range of vertebrates that supported this hypothesis. Our results have implications for the evolution of signalling systems and predator–prey interactions, and, combined with the strong influence that both body mass and metabolism have on a species' ecological niche, suggest that time perception may constitute an important and overlooked dimension of niche differentiation.

Auditory perception of temporal and spectral events in patients with focal left and right cerebral lesions

The auditory perception of temporal and spectral information was studied in subjects with lesions in the temporoparietal region of the left (LH group), or right (RH group) hemisphere ( n = 5 in each group) and in five normal controls. The temporal tasks included gap detection and two complex pattern perception tasks in which subjects had to identify the placement of the two closest tones (separated by the shortest interval) within a sequence of six tones. The spectral tasks involved pitch matching and frequency discrimination. The results showed a “double dissociation”: (1) the LH group was impaired in their ability to perceive temporal information, but the perception of spectral information was normal, and (2) the RH group was impaired in their ability to perceive spectral information, but the perception of temporal information was normal. The findings are consistent with the notion that temporal processing is a function of left-hemisphere structures and that spectral processing is a function of right-hemisphere structures.

Age as a factor in the perception of temporal information in speech

Many older people have greater difficulty processing speech at suprathreshold levels than can be explained by audiometric configurations. Some of the difficulty may involve temporal information. This information can cue “rapid” versus "“rabid” longer first vowel and shorter silent closure cue “rabid”; shorter vowel and longer silence cue “rapid.” Productions of “rabid” were low‐pass filtered at 3500 Hz, and edited to create vowel and closure duration continua. Pure tone audiograms and speech discrimination scores were used to select the ten best hearing subjects among 50 volunteers over age 55. Randomizations of the stimuli were presented for labeling to this group, and to ten normal hearing volunteers under age 25 at 60 and 80 dB HL. Results show highly significant interactions of age with the other factors. These data indicate that the use of temporal information could be more fully exploited in audiological evaluations, and that age may affect which cues are used by a given subject in speech perception. [Work supported by NIH and by VA RER&D.]