Transfer from discrimination under hunger to discrimination under thirst: The role of expectancy and habit

The experimental group (Group HA-TA) received food (F) and water (W) rewarded trials in an alternating sequence under hunger in Phase 1 and under thirst in Phase 2. Group HA-TA ran faster on F than on W trials in Phase 1, and faster on W than on F trials in Phase 2. Early in Phase 2 the difference between speeds on W and F trials was larger for Group HA-TA than for a group which received no runway training in Phase 1 (Group HO-TA), but later in Phase 2 this difference was larger for Group HO-TA than for Group HA-TA. Also in Phase 2 the difference between speeds on W and F trials was larger for Group HA-TA than for a group which received a random sequence of F and W trials under hunger in Phase 1, and smaller for Group HA-TA than for a group which received alternating F and W trials under thirst in both phases. To interpret these results it was assumed that for Group HA-TA the expectancies of reward formed in Phase 1 facilitated development of alternation performance in Phase 2, but that the S-R associative connections formed in Phase 1 inhibited ultimate development of alternation performance in Phase 2.     

Reversal learning as a function of changed reward location or changed drive

In two experiments, rats were trained with food in one location (e.g., black alley) and water in another location (white alley) under hunger or thirst. Subsequently, either the locations of the rewards were reversed, or the drive was changed (from hunger to thirst or thirst to hunger). Reversal of instrumental responses took considerably longer when drive was changed and rewards remained in the same locations than when reward locations were reversed. These results were interpreted as indicating that the animal's internal representations of the rewards received in each location transfer when drive is changed. These internal-reward representations interfere with reversal learning by eliciting the responses which were conditioned to them in Phase 1. Because the values of food and water reverse when drive is changed from hunger to thirst or vice versa, it was suggested that the reward representations surviving the drive shift are cognitive representations of the specific events received (food or water), independent of the value of the rewards under either hunger or thirst.     

Retention interval and intertrial interval in a serial learning or delayed discrimination task

In each of four experiments, rats were provided with the same three-event decreasing series (18-1-0) of 0.045-g food pellets in a runway. Tracking, running fast to 18 pellets and running slow to 1 and 0 pellets, was investigated as a function of the temporal interval elapsing between the events of the series (the retention interval), shifts in retention interval, and number of trials each day (or the intertrial interval), a trial being defined as presentation of each of the three events of the series. Neither retention interval, which varied from 15 s to 30 min in various investigations, nor shifts in retention interval affected tracking when only one trial was given each day. But when more than one daily trial was given, tracking was acquired more slowly and was disrupted by a shift in retention interval from 15 s to 5 min. Tracking was also disrupted by a shift from one to two trials each day. These results indicate that when given one 18-1-0 trial each day, the rat partitions events on a first-event/subsequent-event basis; that little forgetting occurs even at long retention intervals; that somewhat different memories signal events when one or more than one 18-1-0 trial occurs each day; and that retention interval deficits can arise owing to the same or similar memories' signaling different events. The results described limit the generality of three hypotheses suggested in two recent investigations: that as retention interval increases, rats find it increasingly difficult to remember and utilize serial position cues; that tracking in serial tasks is not influenced by number of trials each day; and that there are specific stimuli associated with each retention interval which, when changed, necessarily disrupt performance.     

Shock preexposure and the reduced effectiveness of shock

In three experiments experience with shock was shown to reduce the effectiveness of shock as a reinforcer or motivator. In Experiment 1 rats were given signaled shock in a box separate from the runway where they were subsequently punished. These rats were less suppressed by shock punishment than rats that had no previous shock experience. In Experiment 2 preshocked rats were less suppressed by punishment and were slower to learn an escape-avoidance response than nonpreshocked rats, whether the preshock was signaled or unsignaled. In Experiment 3 as number of CS-shock pairings increased, fear of the CS decreased as did fear of the context. These results suggest that some central adaptation process produced by experience with shock reduces the effectiveness of shock as a reinforcer whenever shock is used repeatedly. This is independent of other effects, such as context blocking, that can affect responding after shock preexposure.     

Replicated Findings and Future Directions for Intergenerational Studies: Closing Comments

This commentary summarizes findings from four papers that set out to replicate, albeit not with identical measures or sampling criteria, research on several questions in the multigenerational study of antisocial behavior by children and child-rearing strategies by parents. The weight of the evidence from our studies indicates some degree of intergenerational continuity in behavior. We observed that adjacent generations G1 and G2 are similar with respect to their styles of parenting and that adjacent generations G2 and G3 are similar with respect to antisocial behavior. In addition, the G2 parent's parenting style plays an important role in mediating or transferring the risk of antisocial behavior across the generations. Implications and directions for future research are discussed.     

Putting the “We” Into Well‐being: Using Collectivism‐Themed Measures of Well‐Being Attenuates Well‐being's Association With Individualism

Studies repeatedly have documented that societal well‐being is associated with individualism. Most of these studies, however, have conceptualized/measured well‐being as individual life satisfaction—a type of well‐being that originates in Western research traditions. Drawing from the latest research on interdependent happiness and on family well‐being, we posit that people across cultures pursue different types of well‐being, and test whether more collectivism‐themed types of well‐being that originate in Confucian traditions also are associated with individualism. Based on data collected from 2,036 participants across 12 countries, we find support for the association between individual life satisfaction and individualism at the societal level, but show that well‐being's association with individualism is attenuated when some collectivism‐themed measures of well‐being are considered. Our article advances knowledge on the flourishing of societies by suggesting that individualism may not always be strongly linked with societal well‐being. Implications for public policies are signaled.     

Cues produced by reward and nonreward and temporal cues influence responding in the intertrial interval and to the conditioned stimulus

Rats in a Pavlovian situation were trained under three different reward schedules, at either a 30 s or a 90 s intertrial interval (ITI): Consistent reward (C), 50% irregular reward (I), and single alternation of reward and nonrewarded trials (SA). Activity was recorded to the conditioned stimulus (CS) and in all 10 s bins in each ITI except the first 10 s bin. Responding increased progressively over the bins of the 90 s ITI indicating a role for temporal cues in the ITI. Single alternation patterning (SAP), more vigorous responding on rewarded than on nonrewarded trials, occurred in the ITI as well as to the CS and differed little at the 30 s and 90 s ITI. The occurrence of SAP to the CS and, as shown here for the first time, in the ITI along with the findings for the C and I schedules, indicate three matters of importance. First, along with other cues such as temporal cues, behavior is influenced by cues associated with reward and nonreward both in the ITI and when the CS is presented. Second, as the percentage of reward associated with these cues increases so too does vigor of responding. Finally, if the cues produced by reward events are memories the retrieval cues for such memories are present in the ITI as well as when the CS is presented. Considerations are advanced indicating that reward produced cues may influence responding in the Pavlovian situation not only under regular schedules such as the SA schedule, but under all schedules. Indeed, such cues may more validly signal reward and nonreward than the CS itself.