Table 2.

The shape and line exemplars used for the various stages of the attentional set-shifting paradigm in Experiments 1 and 2

DiscriminationExemplars
Experiment 1
 SimpleS1+ S2−
 Simple reversalS1− S2+
 Series of compound discriminations (CD1,CD2)
 Compound discrimination prior to surgery (CD3)S5+ S6−
L5 L6
 Surgery
  Retention test (CD3)S5+ S6−
L5 L6
  Two novel compound discriminations (IDS1,IDS2)
  Compound discrimination prior to EDS (IDS3)S11+ S12−
L11 L12
  Probe testS11+ S12−
L13 L14
  Extra-dimensional shift (EDS1)L15+ L16−
S15 S16
  Compound reversal (EDS1R)L15− L16+
S15 S16
  Two novel compound discriminations (IDS4,5) and reversals (IDS4R,5R)
  Compound discrimination prior to EDS2 (IDS5R)L19− L20+
S19 S20
  Second extra-dimensional shift (EDS2)S21+ S22−
L21 L22
  Compound reversal (EDS2R)S21− S22+
L21 L22
Experiment 2
 SimpleP1+ P2−
 Simple reversalP1− P2+
 Surgery
  Retention testP1− P2+
  Compound discrimination (IDS1)S1+ S2−
L1 L2
  Two novel compound discriminations (IDS2,IDS3)
  Compound discrimination prior to compound reversal (IDS4)S7+ S8−
L7 L8
  Compound reversal (IDS4R)S7− S8+
L7 L8
  Compound discrimination (IDS5)S9− S10+
L9 L10
  Compound reversal (IDS5R)S9+ S10−
L9 L10
  Probe testS9+ S10−
L11 L12
  Extra-dimensional shift (EDS)L13+ L14−
S13 S14
  Compound reversal (EDSR)L13− L14+
S13 S14
  • The examples given illustrate the precise sequence of discriminations for those monkeys trained initially on “shapes.”

  • S, L, Dimensions of shape and line, respectively; P, pattern; 1–22, individual line and shape exemplars; +, −, reinforcement value of the stimulus. Letters and numbers in bold indicate which dimension is relevant.