Figure 1.

Different decay of punishment- and relief-memory. (a) Schematic of experimental design. (b) Punishment- and relief-memory assayed after retention periods of either 25, 50, 75, 240 min, or 24 h. Light shading indicates a difference from the scores at the earliest retention period (25 min), lack of fill indicates lack of significance from chance (i.e. from zero). For the 240 min retention period, relief-memory scores were neither different from the scores obtained at 25 min, nor from zero (hatched fill). Box-whisker plots (see §2 for details) show learning indices, positive values indicating conditioned approach to the trained odour (i.e. relief-memory) and negative values conditioned avoidance (i.e. punishment-memory). *p < 0.05 in KW-tests.