The Qualitative Order of Time

Rubin (1939) shows that temporal displacement is a variant of the perceptu­al structures that give appearances an order on the grounds of their qualita­tive features. Rubin presents three noises in a series of successions, varying their relative position and the temporal interval between them from 25 to about 300 msec. Two noises are identical, as in the sequence Aj-B-A^ At long intervals (300 msec.) between each of the three noises, there is no difference between the perceptual order and the stimulus sequence. For short inter­vals, the perceptual order changes into Aj-A₂-B or B-Aj-A₂. Rubin found that all other conditions being equal, the displacement regards the noises whose interval is considerably shorter than the interval that is between them and the third noise. For example, if the interval between Aj and B amounts to 294 msec. and the interval between B and A₂ amounts to 36 msec., one perceives A₁-A₂-B instead of B-Aj-A₂. Moreover, if two noises are more likely to be dis­placed when their interval does not exceed 100-150 msec., the influence of A₁ on A₂ because of qualitative similarity takes place if the interval A₁-B does not exceed 300 msec.

Rubin’s results confirm the key concept of Benussi’s theory. Time percep­tion is the perception of places that events fill in a temporal ordering according to their qualitative features. The relations between the events due to qualita­tive similarity determine the phenomenal relief and the temporal order of the events. Rubin found that for certain temporal values, the perceived temporal order coincides with the physical order of the stimuli and, above all, that if this is not the case, subjects do not feel they are undergoing an illusion. The succes­sion of events in a temporal displacement has the same compelling perceptual reality as any other in which the temporal relations correspond to the stimulus sequence ([1939] 1949: 334). The subjects have the same feeling of reality as ever.

Vicario (1973a: 64k) collects new experimental evidence that extends this interpretation of temporal displacement as a consequence of the structure of phenomena. Vicario employs pure tones of varying pitch and duration to construct sequences of three tones and manipulates the increase (decrease) of duration of each tone as well as the pitch distance from the tones at the be­ginning and the end of the sequence to the intermediate tone. The sequences are presented in two variants: a-b-a or b-a-b, where a denotes a high-pitched tone, like A₆ (1760 Hz) or G₆ (1568 Hz), while b denotes a low-pitched tone, like E₂ (82.4 Hz). The aim is to discover the factors that underlie the structure of temporal displacement and the direction of change in the temporal position. The interpretation of the phenomenon in terms of structure, in the same sense of the structures of causality perception, is supported by the fact that no dis­placement occurs with durations from 500 to 300 msec. As duration decreases, the temporal positions of the events change, because the dependence of posi­tions in time upon the qualitative relations becomes more compelling than the individual localization of the single tones in the stimuli succession. Be­sides, Vicario finds the specific phenomenal temporal unit of the phenomenal structure: 150-100 msec. In other words, this is the greatest interval between the first and the third tone at which their unification is forced upon the subject because of pitch similarity. Therefore this is the value, expressed as the optimal stimulus condition, at which the perceptual structure of temporal localization sets to zero, as it were, the correspondence to the actual succession of stimuli it usually conveys.

Tonal distance is a factor that accounts for the structure. The number of displacements increases as the tonal distance between the tones at the end of the sequence and the intermediate tone increases. For optimal durations, the qualitative relation due to pitch similarity is so forced on subjects that it compels a perceptual restructuration of the sequence. The sequence appears as a very short scale where the intermediate tone with the different pitch is dis­placed at one end of the succession. The perceptual relief of pitch difference is one of the factors that account for the direction of displacement, although its influence is not straightforward. It is plausible to assume that higher tones are more noticeable than lower tones, hence at optimal durations the higher- pitched tones should always be perceived in the first positions for both vari­ants of the displacement. In the a-b-a variant there should only be the positive displacement of b, while in the b-a-b variant there should only be the negative displacement of a. However, Vicario observes that negative displacements oc­cur in the first variant and that positive displacements occur for half of the cases in the second variant. He suggests that these results can be accounted for by assuming that the perceptual relief of pitch competes against the tonal grouping, thus inducing one to more likely perceive a couple of tones instead of single tones. In the first variant, these factors cooperate. The tone b appears at the end of the sequence, because it is lower-pitched and segregated against the tones a, which are grouped together as a tonal pair. In the second variant, a is equally perceived at the beginning and at the end of the sequence, because it is displaced either positively for the higher-pitch relief or negatively for being dissimilar, hence it is segregated against the tones b. As far as the direction of displacement is concerned, Vicario concludes that lower pitch and segregation are the factors of positive displacement, while higher pitch and the belonging­ness of a tonal pair are the factors of negative displacement. Therefore, tonal distance, qualitative similarity and perceptual relief of pitch are the features on which the structure of temporal localization is founded.

Source: Calì Carmelo (2017), Phenomenology of Perception: Theories and Experimental Evidence, Brill.