The investigators from this study have demonstrated how rats learned fear through social transmission with memory retrieval, which illustrate pervious study from Knapska et al., that claimed rat shows increased level of amygdala (responsible for memory and emotion) activity as well as fear learning after they have interacted with a conditioned cage-mate. The present study is further developed whether a cue (a tone) could come to elicit fear expression (freezing) from the fear conditioned by proxy (FCbP) rat through observing a fear conditioned rat (FC)’s response, as well as to examine a subsequent tone-shock pairing fear association along with the pervious study’s assumption. Both studies believed observational learning is an important key to acquire fear.
Experimental design
Investigators have controlled the setting well in order to achieve a high level of internal validity with standardised setting of the experiment environment. Apart from the temperature and humidity of the cages were controlled, they have maintained a 12-hour/12-hour light/dark cycle with food, also allowed the rats to interact freely with each other, these settings permit to minimise confounding variables and maximise the external validity of the study because the rats were placed in similar environmental setting like if they were not in an experiment. In additional, the freezing behaviour was manually scored by two individual raters who knew nothing about the experimental condition. This has also maximised the reliability of the scores as well as prevented bias.
The results
From the first experiment, the result did not show a great level of effect a FC’s fear memory retrieval on a FCbP’s behaviour to the conditioned stimulus as the hypothesis stated at the beginning. Even though the FCbP rats froze considerably more to the tone than their naive cage-mates, F (1.26) = 8.486, p < .05, it does not
References: Bandura, A. (1986). Social foundations of thought and action: A social cognitive theory. Englewood Cliffs, NJ: Prentice Hall. Bruchey A. K., Jones C.E. & Monfils M.H. (2010). Fear conditioning by-proxy: Social transmission on fear during memory retrieval. Behavioural Brain Research, 214, 80-84. Guzman Y.F., Tronson N.C., Guedea A., Huh K.H., Gao C., Radulovic J., (2009). Social modelling of conditioned fear in mice by non-fearful conspecifics. Behavioural Brain Research, 1, 173-178. Knapska E., Mikosz M., Werka T., Maren S., (2010). Social modulation of learning in rats. Learning and memory, 17, 35-42. Knapska E., Nikovlaev E., Boguszewski P., Walasek G., Blaszczk J., Kacmarek L. et al. (2006) Between-subject transfer of emotional information evokes specific pattern of amygdala activation. Proc Natl Acad Sci USA, 103, 3858-3862.