Inhibitory effects of repeating color and shape: Inhibition of return or repetition blindness?

Author(s):  
Elaine Fox ◽  
Jan-Willem de Fockert
2006 ◽  
Vol 23 (3-4) ◽  
pp. 489-493 ◽  
Author(s):  
LUIZ HENRIQUE M. DO CANTO-PEREIRA ◽  
GALINA V. PARAMEI ◽  
EDGARD MORYA ◽  
RONALD D. RANVAUD

Inhibitory effects have been reported when a target is preceded by a cue of the same color and location. Color-based inhibition was found using red and blue nonisoluminant stimuli (Law et al., 1995). Here we investigate whether this phenomenon depends on the chromatic subsystem involved by employing isoluminant colors varying along either the violet-yellow or purple-turquoise cardinal axis. Experiment 1 replicated Law et al.'s study: After fixating magenta, either a red or blue cue was presented, followed by a magenta “neutral attractor,” and, finally, by a red or blue target. In Experiment 2, violet and yellow, cue or target, varied along a tritan confusion line in the CIE 1976 chromaticity diagram. In Experiment 3, purple and turquoise, cue or target, varied along a deutan confusion line in the CIE 1976 chromaticity diagram. Normal trichromats (n = 19) participated in all three experiments. In Experiment 1, color repetition indeed resulted in longer reaction times (RTs) (4.7 ms, P = 0.038). In Experiment 2, however, no significant color repetition effect was found; RTs to violet and yellow were not significantly different, though tending toward slower responses (2 ms) for violet repetition but faster (5 ms) for yellow. Experiment 3 also showed no color repetition effect (P = 0.58); notably, RTs were overall faster for purple than for turquoise (22 ms, P < 0.0001). Furthermore, responses tended to be slower for purple repetition (4 ms, P > 0.05), but faster for turquoise (7 ms, P > 0.05). These findings demonstrate that color repetition is not always inhibitory but may turn facilitatory depending on the colors employed. The results indicate that disengagement of attention is an unlikely mechanism to be the sole explanation of previously reported color-based inhibition of return. We suggest a complementary, perceptual explanation: response (dis)advantage depends on whether the stimuli are isoluminant and on the opponent chromatic subsystem involved. The choice of the colors employed and the cue-attractor-target constellation also may be of significance.


2000 ◽  
Vol 12 (4) ◽  
pp. 648-663 ◽  
Author(s):  
Giovanni Berlucchi ◽  
Leonardo Chelazzi ◽  
Giancarlo Tassinari

Detection reaction time (RT) at an extrafoveal location can be increased by noninformative precues presented at that location or ipsilaterally to it. This cue-induced inhibition is called inhibition of return or ipsilateral inhibition. We measured detection RT to simple light targets at extrafoveal locations that could be designated for covert orienting by local or distant cues. We found that cue-induced inhibition co-occurred in an additive fashion with the direct effects of covert orienting, i.e., it detracted from facilitation at attended locations and increased the disadvantage for unattended locations. Thus, cue-induced inhibition cannot be suppressed by a volitional covert orienting to the cued location; the cooccurrence of different facilitatory and inhibitory effects confirms the simultaneous operation of multiple independent, attentional mechanisms during covert orienting.


2000 ◽  
Vol 53 (4) ◽  
pp. 1039-1060 ◽  
Author(s):  
Catherine L. Harris ◽  
Alison L. Morris
Keyword(s):  

Author(s):  
Pınar Ercan ◽  
Sedef Nehir El

Abstract. The goals of this study were to determine and evaluate the bioaccessibility of total anthocyanin and procyanidin in apple (Amasya, Malus communis), red grape (Papazkarası, Vitis vinifera) and cinnamon (Cassia, Cinnamomum) using an in vitro static digestion system based on human gastrointestinal physiologically relevant conditions. Also, in vitro inhibitory effects of these foods on lipid (lipase) and carbohydrate digestive enzymes (α-amylase and α-glucosidase) were performed with before and after digested samples using acarbose and methylumbelliferyl oleate (4MUO) as the positive control. While the highest total anthocyanin content was found in red grape (164 ± 2.51 mg/100 g), the highest procyanidin content was found in cinnamon (6432 ± 177.31 mg/100 g) (p < 0.05). The anthocyanin bioaccessibilities were found as 10.2 ± 1%, 8.23 ± 0.64%, and 8.73 ± 0.70% in apple, red grape, and cinnamon, respectively. The procyanidin bioaccessibilities of apple, red grape, and cinnamon were found as 17.57 ± 0.71%, 14.08 ± 0.74% and 18.75 ± 1.49%, respectively. The analyzed apple, red grape and cinnamon showed the inhibitory activity against α-glucosidase (IC50 544 ± 21.94, 445 ± 15.67, 1592 ± 17.58 μg/mL, respectively), α-amylase (IC50 38.4 ± 7.26, 56.1 ± 3.60, 3.54 ± 0.86 μg/mL, respectively), and lipase (IC50 52.7 ± 2.05, 581 ± 54.14, 49.6 ± 2.72 μg/mL), respectively. According to our results apple, red grape and cinnamon have potential to inhibit of lipase, α-amylase and α-glucosidase digestive enzymes.


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