TOKYO : Japan's consumer sentiment deteriorated in December, a government survey showed on Wednesday, casting doubt on the central bank's view that solid household spending will underpin the economy and justify a rise in interest rates. The results precede the Bank of Japan's policy meeting on Jan. 23-24, when some analysts anticipate a potential interest rate increase from the current 0.25 per cent. An index measuring consumer sentiment fell to 36.2 in December, a 0.2 point drop from the