Stereotypy of spatial movements during noncontingent and contingent reinforcement

Abstract

The degree of stereotypy in the movement patterns of 3 pigeons during noncontingent and contingent periodic food reinforcement was quantified by analyzingthe distribution of turning angles, and by using information and Fourier analyses. The results indicated that (1) movement patterns were less stereotyped during noncontingent than during contingent reinforcement, (2) a reversal to noncontingent reinforcement resulted in a degree of stereotypy comparable to that during the first phase of noncontingent reinforcement, (3) movement patterns were maximally stereotyped immediately after food withdrawal and generally became less stereotyped as reinforcement approached, regardless of whether reinforcement was noncontingent or contingent, and (4) higher frequency movements generally accounted for more variance in the movements during contingent than during noncontingent reinforcement. Greater stereotypy in the movements during contingent reinforcement was likely due to a greater probability that similar movements were reinforced during contingent reinforcement. Momentary changes in the stereotypy of the movements within the interfood interval might reflect changes in the level of arousal.

Regularities in responding during performance of a complex choice task

“…Multiple overlapping measures of response regularity, assessed at multiple time scales and across multiple response options, were included in the analysis to reduce the likelihood of metricspecific artifacts; several of these measures have never previously been applied to behavioral sequences. Fourier analyses of response patterns, which have been used successfully in past studies of behavioral stereotypy/periodicity within operant conditioning tasks (Silva & Pear, 1995;Silva et al, 1996), were not used in the current study because preliminary analyses suggested that the key periodic features of response sequences were more simply and adequately characterized using alternative measures of recurrence. Temporal regularity in responding can arise from intrinsic tendencies to produce rhythmic movements, cyclical movements between response options, and the performance of highly stereotyped movement patterns during responding.…”

“…Past studies of movement regularity during conditioning have described what animals are doing as they acquire or perform responses under basic reinforcement schedules (Blough, 1963;Guthrie & Horton, 1946;Li & Huston, 2002;Li, Krauth, & Huston, 2006;Palya, 1992;Silva & Pear, 1995;Silva et al, 1996). Unsurprisingly, subjects presented with such schedules show greater consistency in response timing when the timing of reinforcement is more predictable (e.g., during FI and FT schedules).…”

“…A minority of researchers has attempted to supplement this approach with more molecular measures of responding during learning (Blough, 1963;Fantino & Royalty, 1987;Newland, 1997;Palya, 1992;Shimp, 1992;Silva & Pear, 1995;Silva, Pear, Tait, & Forest, 1996;Weiss, 1970), and to use such measures to develop alternative theories of conditioning (Galbicka, 1992;Misak & Cleaveland, 2011;Shimp, 1966;Shimp, Fremouw, Ingebritsen, & Long, 1994;Tanno & Silberberg, 2012). For instance, Silva and Pear (1995) analyzed measures of pigeon's spatial trajectories as the birds learned to respond to fixed-time (FT) and fixed-interval (FI) reinforcement schedules and found that movement stereotypy varied as a function of when rewards were delivered and on whether rewards were contingent on pecking. Palya (1992) analyzed the timing of pecks by pigeons performing in hundreds of consecutive sessions with different reinforcement schedules and showed that pigeons consistently pecked at a rate of 3 Hz regardless of schedule.…”

Fourier analysis of movement patterns in pigeons

“…The fact that Fourier analysis compacted the data while quantifying and highlighting the periodicity in those data provides much to recommend it in studies of movement patterns (e.g., Pear, 1985;Scherer et aI., 1992; see also Silva & Pear, 1995). It is also interesting to note that discrete measures of behavior-such as rate of keypecking-give, in comparison with plots of the birds' movements and Fourier analysis, a rather inaccurate impression ofbehavior by indicating that VT, for example, resulted in keypeck levels close to zero during much of the sessions shown in Figure 1.…”

“…In short, it is a powerful analytic tool that might usefully be incorporated with other analytic methods. Moreover, its use and focus on periodicity might enhance the study of phenomena related to movement such as stereotypy and resonance (e.g., Silva & Pear, 1995), as well as aiding in computer simulations and models of movement patterns. For example, through the use of Fourier analysis, the stereotypy of a movement pattern could be defined as the minimum number (or range) of frequencies necessary to account for 80% of the variance in a time series.…”