Effects of lesions of the nucleus accumbens core on inter-temporal choice: Further observations with an adjusting-delay procedure

Nucleus accumbens and delay discounting in rats: evidence from a new quantitative protocol for analysing inter-temporal choice

“…These authors proposed that lesions of the AcbC induce an increase in the rate of delay discounting, resulting in a reduction of the value of delayed reinforcers. The finding of Cardinal et al (2001) has been confirmed in a number of more recent experiments (Pothuizen et al 2005;Bezzina et al 2007Bezzina et al , 2008da Costa Araújo et al 2009. Cardinal and Cheung (2005) and Cardinal and Howes (2005) showed that destruction of the AcbC did not alter the instantaneous value of reinforcers in choice schedules, suggesting that altered sensitivity to reinforcer size cannot account for the effect of AcbC lesions on inter-temporal choice (see below).…”

“…Evidence obtained to date indicates that the power spectrum of oscillations is sensitive to the ratio of reinforcer sizes (q B /q A ; da Costa Araújo et al 2009Araújo et al , 2010Valencia-Torres et al 2011). However, it seems not to be affected by lesions of the AcbC (da Costa Araújo et al 2009Araújo et al , 2010. A secondary aim of the present experiment was to reexamine the effect of AcbC lesions on the power spectrum of cyclical changes in the adjusting delay using different values of q A and q B from those used by da Costa Araújo et al (2009Araújo et al ( , 2010.…”

“…However, it seems not to be affected by lesions of the AcbC (da Costa Araújo et al 2009Araújo et al , 2010. A secondary aim of the present experiment was to reexamine the effect of AcbC lesions on the power spectrum of cyclical changes in the adjusting delay using different values of q A and q B from those used by da Costa Araújo et al (2009Araújo et al ( , 2010. 1 'Immediate' (or 'non-delayed') reinforcement generally signifies that reinforcer delivery is initiated immediately after the index response has been detected by the programming apparatus.…”

“…da Costa Araújo et al (2009Araújo et al ( , 2010 suggested that the pattern of oscillation of d B , analysed using Fourier transform, may provide information about the effects of neurobiological interventions on the organism's adaptation to changing delays to reinforcement. Evidence obtained to date indicates that the power spectrum of oscillations is sensitive to the ratio of reinforcer sizes (q B /q A ; da Costa Araújo et al 2009Araújo et al , 2010Valencia-Torres et al 2011). However, it seems not to be affected by lesions of the AcbC (da Costa Araújo et al 2009Araújo et al , 2010.…”

“…The principal dependent variable, the adjusting delay to the larger reinforcer (d B ), is seen to oscillate during an extended period of training, the amplitude of oscillation gradually declining as d B approaches a quasi-stable value, which is usually taken to represent the indifference delay, d B(50) (Mazur 1987(Mazur , 1988. da Costa Araújo et al (2009Araújo et al ( , 2010 suggested that the pattern of oscillation of d B , analysed using Fourier transform, may provide information about the effects of neurobiological interventions on the organism's adaptation to changing delays to reinforcement. Evidence obtained to date indicates that the power spectrum of oscillations is sensitive to the ratio of reinforcer sizes (q B /q A ; da Costa Araújo et al 2009Araújo et al , 2010Valencia-Torres et al 2011).…”