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Biomedical subjects

J F Knutson

Publications and source records attributed to J F Knutson.

44 records · Page 3Linked to original sources
PubMed1974

Free-operant escape-avoidance of noise by rats.

A series of experiments was conducted to establish free-operant escape-avoidance responding in rats using noise as the stimulus. Naive rats did not acquire a bar-press response on an escape-avoidance of noise schedule. Similarly, free-operant responding established using escape-avoidance of shock was not maintained when noise was substituted for shock. Noise stimuli of 110 dB did maintain responding, but at a lower level than during training, when the noise stimuli had first been paired with shock. Noise stimuli of 97 dB and 87 dB were not effective under those same conditions. Additional rats were trained on a free-operant escape-avoidance schedule of shock and then exposed to a delayed conditioning procedure in which noise was the conditioned stimulus and shock was the unconditioned stimulus. When these subjects were then tested with noise alone, two of the three subjects conditioned and tested with 105-dB noise displayed escape-avoidance of noise, but none of the rats conditioned and tested at 97 dB displayed escape-avoidance of noise. The results suggest that free-operant escape-avoidance of noise can be demonstrated; however, only higher intensity noise stimuli that have been paired with shock are effective.

Journal Article↗
PubMed1970

Aggression during the fixed-ratio and extinction components of a multiple schedule of reinforcement.

Pigeons were trained to key peck for food on multiple reinforcement schedules including components of continuous and fixed-ratio reinforcement and extinction. At the end of the chamber opposite the response key was a restrained target pigeon. The target restraining equipment was designed to record automatically blows struck against the target. When the experimental pigeons were paired with restrained target pigeons they attacked the target. Attack occurred during extinction after both continuous and fixed-ratio reinforcement. Attack also occurred occasionally during fixed-ratio 25 and fixed-ratio 40 and frequently during fixed-ratio 60 and fixed-ratio 120. No attack occurred during fixed-ratio 15 and continuous reinforcement. After a history of stable responding without a target bird present, the introduction of a target bird resulted in severely strained key-peck responding characterized by long periods of neither key pecking nor aggressing.

Aggression↗
PubMedDate not supplied

The association between punitive childhood experiences and hyperactivity.

This study compared the abuse histories and home environments of adult males who had been referred for Attention Deficit-Hyperactivity Disorder (ADHD) with that of their nonADHD siblings. Probands and brothers did not differ in their reporting of physical punishment, discipline, parental rejection, or positive parental contact, nor did they differ in their perception of the general atmosphere of their home environments. These findings were generally replicated in a larger sample of ADHD probands, nonADHD brothers and a group of classmate controls. In addition, the relation between severity of hyperactive and aggressive symptoms and degree of abuse was examined within an ADHD sample. Neither the degree of hyperactive symptoms, the degree of aggressive symptoms, nor the interaction of the two was associated with the amount of physical punishment reported. These data challenge the "scapegoat" or "target child" hypothesis prevalent in the child abuse literature by suggesting that punitive parenting may not be significantly controlled by the behavioral characteristics of ADHD children.

Adult↗
PubMedDate not supplied

Musical backgrounds, listening habits, and aesthetic enjoyment of adult cochlear implant recipients.

This paper describes the listening habits and musical enjoyment of postlingually deafened adults who use cochlear implants. Sixty-five implant recipients (35 females, 30 males) participated in a survey containing questions about musical background, prior involvement in music, and audiologic success with the implant in various listening circumstances. Responses were correlated with measures of cognition and speech recognition. Sixty-seven implant recipients completed daily diaries (7 consecutive days) in which they reported hours spent in specific music activities. Results indicate a wide range of success with music. In general, people enjoy music less postimplantation than prior to hearing loss. Musical enjoyment is influenced by the listening environment (e.g., a quiet room) and features of the music.

Adult↗