The associated nontargets effect: Evidence of nontarget processing at and beyond the level of letter recognition

In four visual search tasks participants were asked to make a target response if either of two targets was present and to make a nontarget response if neither target was present. Some target-absent displays included only nontarget stimuli or features that never occurred in the same displays as targets, whereas other target-absent displays included nontarget stimuli or features that did sometimes occur with targets. Nontarget responses were reliably faster in the former case than in the latter. This “associated nontargets effect” indicates that nontargets are not simply classified as nontargets but in addition are discriminated from one another. Current visual search models may underestimate the degree to which nontargets are processed during search.     

On the effectiveness of and preference for punishment and extinction components of function-based interventions

The current study describes an assessment sequence that may be used to identify individualized, effective, and preferred interventions for severe problem behavior in lieu of relying on a restricted set of treatment options that are assumed to be in the best interest of consumers. The relative effectiveness of functional communication training (FCT) with and without a punishment component was evaluated with 2 children for whom functional analyses demonstrated behavioral maintenance via social positive reinforcement. The results showed that FCT plus punishment was more effective than FCT in reducing problem behavior. Subsequently, participants' relative preference for each treatment was evaluated in a concurrent-chains arrangement, and both participants demonstrated a dear preference for FCT with punishment. These findings suggest that the treatment-selection process may be guided by person-centered and evidence-based values.     

A comparison of masking by visual and transcranial magnetic stimulation: implications for the study of conscious and unconscious visual processing

Visual stimuli as well as transcranial magnetic stimulation (TMS) can be used: (1) to suppress the visibility of a target and (2) to recover the visibility of a target that has been suppressed by another mask. Both types of stimulation thus provide useful methods for studying the microgenesis of object perception. We first review evidence of similarities between the processes by which a TMS mask and a visual mask can either suppress the visibility of targets or recover such suppressed visibility. However, we then also point out a significant difference that has important implications for the study of the time course of unconscious and conscious visual information processing and for theoretical accounts of the processes involved. We present evidence and arguments showing: (a) that visual masking techniques, by revealing more detailed aspects of target masking and target recovery, support a theoretical approach to visual masking and visual perception that must take into account activities in two separate neural channels or processing streams and, as a corollary, (b) that at the current stage of methodological sophistication visual masks, by acting in more highly specifiable ways on these pathways, provide information about the microgenesis of form perception not available with TMS masks.     

The man who listens to behavior: folk wisdom and behavior analysis from a real horse whisperer

The popular novel and movie The Horse Whisperer are based on the work of several real-life horse whisperers, the most famous of whom is Monty Roberts. Over the last 50 years, Roberts has developed a technique for training horses that is both more effective and less aversive than traditional training techniques. An analysis of Roberts' methods (as described in his book, The Man Who Listens to Horses) indicates a deep understanding of behavioral principles including positive reinforcement, timeout, species-specific defense reactions, “learned helplessness,” and the behavioral analysis of language. Roberts developed his theory and techniques on the basis of personal experience and folk wisdom, and not as the result of formal training in behavior analysis. Behavior analysts can clearly learn from such insightful yet “behaviorally incorrect” practitioners, just as such practitioners can benefit from the objective science of behavior analysts.     

Posttraining Electrical Stimulation of Vagal Afferents with Concomitant Vagal Efferent Inactivation Enhances Memory Storage Processes in the Rat

Peripherally administered or released substances that modulate memory storage, but do not freely enter the brain, may produce their effects on memory by activating peripheral receptors that send messages centrally through the vagus nerve. Indeed, vagus nerve stimulation enhances memory performance, although it is unclear whether this effect is due to the activation of vagal afferents or efferents. To eliminate the possible influence of descending fibers on memory storage processes, rats were implanted with cuff electrode/catheter systems along the left cervical vagus. Forty-eight hours following surgery, each animal received a 3.0-μl infusion (1.0 μl/min) of either lidocaine hydrochloride (75.0 mM) or isotonic saline below the point of stimulation. Animals were then trained 10 min later on an inhibitory-avoidance task with a 0.75-mA, 1.0-s foot shock. Sham stimulation or vagus nerve stimulation (0.5-ms biphasic pulses; 20.0 Hz; 30 s; 0.2, 0.4, or 0.8 mA) was administered immediately after training. Memory, tested 24 h later, was enhanced by stimulation whether descending vagus nerve fibers were inactivated or not. Both lidocaine- and saline-infused groups showed an intensity-dependent, inverted-U-shaped pattern of retention performance, with the greatest effect observed for 0.4 mA (U= 9,p< .05, andU= 7,p< .01, respectively). Additionally, animals that received lidocaine infusions, but no vagus nerve stimulation, showed impaired memory compared to the performance of saline-infused control animals (U= 11,p< .05). Together, these findings suggest that vagal afferents carry messages about peripheral states that lead to the modulation of memory storage and that the memory-enhancing effect produced by vagus nerve stimulation is not mediated via the activation of vagal efferents.     

Synergistic effects of ethanol and cocaine on brain stimulation reward.

The effects of two widely abused drugs, ethanol and cocaine, were examined alone and in combination on intracranial reward processes. In agreement with previous research, higher doses of both cocaine and ethanol alone produced facilitation of behavior maintained by brain stimulation reward. Low intraperitoneal doses of ethanol and cocaine, which alone did not affect performance, were found to reduce stimulation reward threshold and modestly increase response rate. The enhancement of brain stimulation reward by the combination of ethanol and cocaine suggests that both drugs may produce their rewarding effects through common neuronal substrates and that they may potentiate the abuse of each other.     

Histological data: Hollard and Davison (1971)

As Mogenson and Cioé (1977) have assumed that our electrodes aimed at the ectostriatum (Hollard and Davison, 1971) were actually located there, we feel that a presentation of the histological data is necessary. Following termination of further experiments (Hollard, 1974) the pigeons, numbered 93, 95, and 119, were sacrificed and perfused with saline followed by 10% formalin. Sections, 50 microns thick, were cut on a freezing microtome. Prints were made by mounting each unstained section of a microscope slide and placing them in a standard photographic enlarger. The electrode tips of Pigeons 93 and 119 were located in the paleostriatal complex. The sections of Pigeon 95 were damaged and precise localization was not possible. Further work in this laboratory has also found that, using the same coordinates, electrode tips tend to fall in the paleostriatum, rather than in the more dorsal ectostriatum at which they are aimed. The paleostriatal placements tended to sustain self-stimulation, whereas others located in the ectostriatum sustained relatively low or unstable rates.     

Parameters affecting the maintenance of negatively reinforced key pecking

Three negative reinforcement experiments employing a key-peck response are described. In Experiment I, pigeons shocked on the average of twice per minute (imposed condition) could produce, by pecking a key, an alternate condition with correlated stimuli. Delayed shocks were added, across sessions, to the alternate condition until pecking stopped. Two of three pigeons continued to peck despite a 100% increase in shock frequency. In Experiment II, pigeons were shocked in the imposed condition four times per minute. The postresponse delay to shock was held constant by delivering, in the alternate condition, the next shock, or the next two, three, or four shocks from the imposed-condition shock schedule. All three subjects continued to peck with no change in delay to the first two postresponse shocks but with a 75% reduction in shock frequency. In Experiment III, a response produced an immediate shock followed by a shock-free period. Three of four subjects continued to respond despite reduced delay to shock. Delay-to-shock or shock-frequency reduction was sufficient to maintain key pecking, but neither was necessary. The conditions that negatively reinforce the pigeon's key peck were similar to conditions that negatively reinforce the rat's bar press.     

AVERSIVE CONTROL: A SEPARATE DOMAIN?

Traditionally, aversive control has been viewed as a separate domain within behavior theory. Sometimes this separateness has been based upon a distinction between reinforcement and punishment, and sometimes upon a distinction between positive and negative reinforcement. The latter is regarded here as the more compelling basis, due to some inherent procedural asymmetries. An approach to the interpretation of negative reinforcement is presented, with indication of types of experiments that support it and that also point to promising directions for further work. However, most of the interpretive issues that arise here are relevant to positively reinforced behavior as well. These include: possible reformulation of the operant/respondent distinction; the place of emotional concepts in behavior analysis; the need for simultaneous, complementary analysis on differing time scales; the understanding of behavioral situations with rewarding or aversive properties that depend as much upon the contingencies that the situations involve as upon the primary rewarding or aversive stimuli that they include. Thus, an adequate understanding of this domain, which has been traditionally viewed as distinct, has implications for all domains of behavior-analytic theory.